 | MISUMI TatsuhiroDepartment of Science Associate Professor | ||
Last Updated :2024/05/15
Researcher Information
Degree
- Ph.D.（2012/03 Kyoto University）
- M.Sc.（2009/03 Kyoto University）
- B.Sc.（2007/03 The University of Tokyo）
URL
Research funding number
- 80715152
J-Global ID
Profile
Ph.D, Physics
Associate Professor, Facult of Science and Engineering, Kindai University, 2021
Junior Associate Professor, Faculty of Engineering Science, Akita University, 2015
Assistant Professor, Hiyoshi Department of Physics, Keio University, 2013
Postdoctoral Research Associate, BNL / JSPS PD Fellow for Research Abroad, 2012
JSPS DC1 Research Follow, Yukawa Institute for Theoretical Physics, 2009
Ph.D. Physics Department of Physics, Kyoto University, 2012
M.S. Physics Department of Physics, Kyoto University, 2009
B.A. Physics Department of Physics, The University of Tokyo, 2007
Research Interests
- Quantum Field Theory Elementary Particle Theory Lattice Field Theory General theory of fields and particles
Research Areas
Academic & Professional Experience
- 2021/04 - Today Kindai UniversityFaculty of Science and EngineeringAssociate Professor
- 2021/04 - Today Keio UniversityResearch Centers and Institutes Research and Education Center for Natural SciencesVisiting Associate Professor
- 2021/04 - 2022/03 Akita UniversityGraduate School of Engineering and ScienceLecturer
- 2021/04 - 2021/09 Hiroshima UniversityGraduate School of ScienceVisiting Associate Professor
- 2015/06 - 2021/03 Keio UniversityResearch and Education Center for Natural ScienceVisiting Assistant Professor
- 2015/06 - 2021/03 Akita UniversityGraduate School of Engineering ScienceTenured Junior Associate Professor (Lecturer)
- 2017/04 - 2020/03 RIKENiTHEMSVisiting Researcher
- 2013/05 - 2015/05 Keio UniversityHiyoshi Department of PhysicsAssistant professor
- 2012/04 - 2013/04 JSPS/Brookhaven National LaboratoryPhysics DepartmentJSPS Postdoctoral Research Fellow for Research Abroad / Postdoctoral Researcher
- 2009/04 - 2012/03 YITP, Kyoto University/JSPSParticle Physics GroupJSPS DC1 Research Associate
- 2010/04 - 2011/03 Brookhaven National Laboratory/JSPSPhysics DepartmentJSPS Excellent Young Researchers Overseas Visit Program, Special Research Fellow/Junior Research Associate
Education
- 2007/04 - 2012/03 Kyoto University Graduate School of Science Department of Physics
- 2003/04 - 2007/03 The University of Tokyo Faculty of Science Department of Physics
Association Memberships
Published Papers
- Jun Yumoto; Tatsuhiro MisumiProgress of Theoretical and Experimental Physics Oxford University Press (OUP) 2024 (2) 023B03 2024/01 [Refereed]
We explore the relationship between lattice field theory and graph theory, placing special emphasis on the interplay between Dirac and scalar lattice operators and matrices within the realm of spectral graph theory. Beyond delving into fundamental concepts of spectral graph theory, such as adjacency and Laplacian matrices, we introduce a novel matrix called an “antisymmetrized adjacency matrix”, specifically tailored for cycle digraphs (T1 lattice) and simple directed paths (B1 lattice). The nontrivial relationship between graph theory matrices and lattice operators shows that the graph Laplacian matrix mirrors the lattice scalar operator and the Wilson term in lattice fermions, while the antisymmetrized adjacency matrix, along with its extensions to higher dimensions, is equivalent to naive lattice Dirac operators. Building upon these connections, we provide rigorous proofs for two key assertions: (i) The count of zero-modes in a free lattice scalar operator coincides with the zeroth Betti number of the underlying graph (lattice). (ii) The maximum count of Dirac zero-modes in a free lattice fermion operator is equivalent to the cumulative sum of all Betti numbers when the D-dimensional graph results from a Cartesian product of cycle digraphs (T1 lattice) and simple directed paths (B1 lattice). - Jun Yumoto; Tatsuhiro MisumiProgress of Theoretical and Experimental Physics Oxford University Press (OUP) 2023 (9) 093B01 2023/08 [Refereed]
Abstract We propose a new conjecture on the relation between the exact Dirac zero-modes of free and massless lattice fermions and the topology of the manifold on which the fermion action is defined. Our conjecture claims that the maximal number of exact Dirac zero-modes of fermions on finite-volume and finite-spacing lattices defined by a discretizing torus, hyperball, their direct-product space, and hypersphere is equal to the summation of the Betti numbers of their manifolds if several specific conditions on lattice formulations are satisfied. We start with reconsidering exact Dirac zero-modes of naive fermions on the lattices whose topologies are a torus, hyperball, and their direct-product space (TD × Bd). We find that the maximal number of exact zero-modes of free Dirac fermions is in exact agreement with the sum of Betti numbers $\sum ^{D}_{r=0} \beta _{r}$ for these manifolds. Indeed, the 4D lattice fermion on a torus has up to 16 zero-modes while the sum of Betti numbers of T4 is 16. This coincidence holds also for the D-dimensional hyperball and their direct-product space TD × Bd. We study several examples of lattice fermions defined on a certain discretized hypersphere (SD), and find that it has up to two exact zero-modes, which is the same number as the sum of Betti numbers of SD. From these facts, we conjecture the equivalence of the maximal number of exact Dirac zero-modes and the summation of Betti numbers under specific conditions. We discuss a program for proof of the conjecture in terms of Hodge theory and spectral graph theory. - Toshiaki Fujimori; Syo Kamata; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPhysical Review D American Physical Society (APS) 107 (10) 105011 2470-0010 2023/05 [Refereed]
We discuss all-order transseries in one of the simplest quantum mechanical systems: a U(1) symmetric single-degree-of-freedom system with a first-order time derivative term. Following the procedure of the Lefschetz thimble method, we explicitly evaluate the path integral for the generating function of the Noether charge and derive its exact transseries expression. Using the conservation law, we find all the complex saddle points of the action, which are responsible for the nonperturbative effects and the resurgence structure of the model. The all-order power-series contributions around each saddle point are generated from the one-loop determinant with the help of the differential equations obeyed by the generating function. The transseries are constructed by summing up the contributions from all the relevant saddle points, which we identify by determining the intersection numbers between the dual thimbles and the original path integration contour. We confirm that the Borel ambiguities of the perturbation series are canceled by the nonperturbative ambiguities originating from the discontinuous jumps of the intersection numbers. The transseries computed in the path-integral formalism agrees with the exact generating function, whose explicit form can be obtained in the operator formalism thanks to the integrable nature of the model. This agreement indicates the nonperturbative completeness of the transseries obtained by the semiclassical expansion of the path integral based on the Lefschetz thimble method. - Syo Kamata; Tatsuhiro Misumi; Naohisa Sueishi; Mithat ÜnsalPhysical Review D American Physical Society (APS) 107 (4) 045019 2470-0010 2023/02 [Refereed]
- Hiromichi Nishimura; Toshiaki Fujimori; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiJournal of High Energy Physics Springer Science and Business Media LLC 2022 (6) 151 2022/06 [Refereed]
The resurgence structure of the 2d O(N) sigma model at large N is studied with a focus on an IR momentum cutoff scale a that regularizes IR singularities in the semiclassical expansion. Transseries expressions for condensates and correlators are derived as series of the dynamical scale Λ (nonperturbative exponential) and coupling λμ renormalized at the momentum scale μ. While there is no ambiguity when a > Λ, we find for a < Λ that the nonperturbative sectors have new imaginary ambiguities besides the well-known renormalon ambiguity in the perturbative sector. These ambiguities arise as a result of an analytic continuation of transseries coefficients to small values of the IR cutoff a below the dynamical scale Λ. We find that the imaginary ambiguities are cancelled each other when we take all of them into account. By comparing the semiclassical expansion with the transseries for the exact large-N result, we find that some ambiguities vanish in the a → 0 limit and hence the resurgence structure changes when going from the semiclassical expansion to the exact result with no IR cutoff. An application of our approach to the ℂPN−1 sigma model is also discussed. We find in the compactified model with the ℤN twisted boundary condition that the resurgence structure changes discontinuously as the compactification radius is varied. - Jun Yumoto; Tatsuhiro MisumiJournal of High Energy Physics Springer Science and Business Media LLC 2022 (2) 1 - 24 2022/02 [Refereed]
We study lattice fermions from the viewpoint of spectral graph theory (SGT). We find that a fermion defined on a certain lattice is identified as a spectral graph. SGT helps us investigate the number of zero eigenvalues of lattice Dirac operators even on the non-torus and non-regular lattice, leading to understanding of the number of fermion species (doublers) on lattices with arbitrary topologies. The procedure of application of SGT to lattice fermions is summarized as follows: (1) One investigates a spectral graph corresponding to a lattice fermion. (2) One obtains a matrix corresponding to the graph. (3) One finds zero eigenvalues of the matrix by use of the discrete Fourier transformation (DFT). (4) By taking an infinite-volume and continuum limits, one finds the number of species. We apply this procedure to the known lattice fermion formulations including Naive fermions, Wilson fermions and Domain-wall fermions, and reproduce the known fact on the number of species. We also apply it to the lattice fermion on the discretized fourdimensional hyperball and discuss the number of fermion species on the bulk. In the end of the paper, we discuss the application of the analysis to lattice fermions on generic lattices with arbitrary topologies, which could lead to constructing a new theorem regarding the number of species. - Toshiaki Fujimori; Masazumi Honda; Syo Kamata; Tatsuhiro Misumi; Norisuke Sakai; Takuya YodaProgress of Theoretical and Experimental Physics Oxford University Press (OUP) 2021 (10) 103B04 2021/10 [Refereed]
Abstract We study a resurgence structure of a quantum field theory with a phase transition to uncover relations between resurgence and phase transitions. In particular, we focus on three-dimensional $\mathcal{N}=4$ supersymmetric quantum electrodynamics (SQED) with multiple hypermultiplets, where a second-order quantum phase transition has recently been proposed in the large-flavor limit. We provide interpretations of the phase transition from the viewpoints of Lefschetz thimbles and resurgence. For this purpose, we study the Lefschetz thimble structure and properties of the large-flavor expansion for the partition function obtained by the supersymmetric localization. We show that the second-order phase transition is understood as a phenomenon where a Stokes and an anti-Stokes phenomenon occur simultaneously. The order of the phase transition is determined by how saddles collide at the critical point. In addition, the phase transition accompanies an infinite number of Stokes phenomena due to the supersymmetry. These features are appropriately mapped to the Borel plane structures as the resurgence theory expects. Given the lessons from SQED, we provide a more general discussion on the relationship between the resurgence and phase transitions. In particular, we show how the information on the phase transition is decoded from the Borel resummation technique. - Masaru Hongo; Toshiaki Fujimori; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPhysical Review B American Physical Society (APS) 104 (13) 2469-9950 2021/10 [Refereed]
- Naohisa Sueishi; Syo Kamata; Tatsuhiro Misumi; Mithat ÜnsalJournal of High Energy Physics Springer Science and Business Media LLC 2021 (7) 096 2021/07 [Refereed]
A<sc>bstract</sc> We investigate the exact-WKB analysis for quantum mechanics in a periodic potential, withN minima onS 1. We describe the Stokes graphs of a general potential problem as a network of Airy-type or degenerate Weber-type building blocks, and provide a dictionary between the two. The two formulations are equivalent, but with their own pros and cons. Exact-WKB produces the quantization condition consistent with the known conjectures and mixed anomaly. The quantization condition for the case ofN -minima on the circle factorizes over the Hilbert sub-spaces labeled by discrete theta angle (or Bloch momenta), and is consistent with ’t Hooft anomaly for evenN and global inconsistency for oddN . By using Delabaere-Dillinger-Pham formula, we prove that the resurgent structure is closed in these Hilbert subspaces, built on discrete theta vacua, and by a transformation, this implies that fixed topological sectors (columns of resurgence triangle) are also closed under resurgence. - Hidetoshi Taya; Toshiaki Fujimori; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiJournal of High Energy Physics Springer Science and Business Media LLC 2021 (3) 082 2021/03 [Refereed]
We study the vacuum pair production by a time-dependent strong electric field based on the exact WKB analysis. We identify the generic structure of a Stokes graph for systems with the vacuum pair production and show that the number of produced pairs is given by a product of connection matrices for Stokes segments connecting pairs of turning points. We derive an explicit formula for the number of produced pairs, assuming the semi-classical limit. The obtained formula can be understood as a generalization of the divergent asymptotic series method by Berry, and is consistent with other semi-classical methods such as the worldline instanton method and the steepest descent evaluation of the Bogoliubov coefficients done by Brezin and Izykson. We also use the formula to discuss effects of time-dependence of the applied strong electric field including the interplay between the perturbative multi-photon pair production and non-peturbative Schwinger mechanism, and the dynamically assisted Schwinger mechanism. - Naohisa Sueishi; Syo Kamata; Tatsuhiro Misumi; Mithat ÜnsalJournal of High Energy Physics 2020 (12) 114 2020/12 [Refereed]
There are two well-known approaches to studying nonperturbative aspects of quantum mechanical systems: Saddle point analysis of the partition functions in Euclidean path integral formulation and the exact-WKB analysis based on the wave functions in the Schr\"{o}dinger equation. In this work, based on the quantization conditions obtained from the exact-WKB method, we determine the relations between the two formalism and in particular show how the two Stokes phenomena are connected to each other: the Stokes phenomenon leading to the ambiguous contribution of different sectors of the path integral formulation corresponds to the change of the "topology" of the Stoke curves in the exact-WKB analysis. We also clarify the equivalence of different quantization conditions including Bohr-Sommerfeld, path integral and Gutzwiller's ones. In particular, by reorganizing the exact quantization condition, we improve Gutzwiller analysis in a crucial way by bion contributions (incorporating complex periodic paths) and turn it into an exact result. Furthermore, we argue the novel meaning of quasi-moduli integral and provide a relation between the Maslov index and the intersection number of Lefschetz thimbles. - Toshiaki Fujimori; Etsuko Itou; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiJournal of High Energy Physics Springer 2020 (08) 011 2020/08 [Refereed]
We investigate the lattice ${\mathbb C} P^{N-1}$ sigma model on $S_{s}^{1}$(large) $\times$ $S_{\tau}^{1}$(small) with the ${\mathbb Z}_{N}$ symmetric twisted boundary condition, where a sufficiently large ratio of the circumferences ($L_{s}\gg L_{\tau}$) is taken to approximate ${\mathbb R} \times S^1$. We find that the expectation value of the Polyakov loop, which is an order parameter of the ${\mathbb Z}_N$ symmetry, remains consistent with zero ($|\langle P\rangle|\sim 0$) from small to relatively large inverse coupling $\beta$ (from large to small $L_{\tau}$). As $\beta$ increases, the distribution of the Polyakov loop on the complex plane, which concentrates around the origin for small $\beta$, isotropically spreads and forms a regular $N$-sided-polygon shape (e.g. pentagon for $N=5$), leading to $|\langle P\rangle| \sim 0$. By investigating the dependence of the Polyakov loop on $S_{s}^{1}$ direction, we also verify the existence of fractional instantons and bions, which cause tunneling transition between the classical $N$ vacua and stabilize the ${\mathbb Z}_{N}$ symmetry. Even for quite high $\beta$, we find that a regular-polygon shape of the Polyakov-loop distribution, even if it is broken, tends to be restored and $|\langle P\rangle|$ gets smaller as the number of samples increases. To discuss the adiabatic continuity of the vacuum structure from another viewpoint, we calculate the $\beta$ dependence of ``pseudo-entropy" density $\propto\langle T_{xx}-T_{\tau\tau}\rangle$. The result is consistent with the absence of a phase transition between large and small $\beta$ regions. - Tatsuhiro Misumi; Jun YumotoPhysical Review D APS 102 (03) 034516 2020/05 [Refereed]
We focus on the four-dimensional central-branch Wilson fermion, which makes good use of six species at the central branch of the Wilson Dirac spectrum and possesses the extra $U(1)_{\overline V}$ symmetry. With introducing new insights we discuss the prohibition of additive mass renormalization for all the six species, SSB of $U(1)_{\overline V}$ in strong-coupling QCD, the absence of the sign problem, and the usefulness for many-flavor QCD simulation. We then construct several varieties of the central-branch fermions and study their properties. In particular, we investigate the two-flavor version, where the Dirac spectrum has seven branches and two species live at the central branch. Although the hypercubic symmetry is broken, the other symmetries are the same as those of the original one. We study this setup in terms of lattice perturbation theory, strong-coupling QCD, the absence of sign problem, and the parameter tuning for Lorentz symmetry restoration. By comparing the properties of the original and two-flavor version, we find that the existence of hypercubic symmetry as well as $U(1)_{\overline V}$ is essential for the absence of additive mass renormalization of all the central-branch species. As the other two-flavor version, we investigate the central-branch staggered-Wilson fermion, which is obtained from the eight-flavor central-branch Wilson fermion via spin diagonalization. We argue that it is free from any additive mass renormalization and is regarded as a minimally doubled fermion with less symmetry breaking. - Masaru Hongo; Toshiaki Fujimori; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPhysical Review B APS 101 (10) 104417 2469-9950 2020/03 [Refereed]
We exhaustively construct instanton solutions and elucidate their properties
in one-dimensional anti-ferromagnetic chiral magnets based on the $O(3)$
nonlinear sigma model description of spin chains with the Dzyaloshinskii-Moriya
(DM) interaction. By introducing an easy-axis potential and a staggered
magnetic field, we obtain a phase diagram consisting of ground-state phases
with two points (or one point) in the easy-axis dominant cases, a helical
modulation at a fixed latitude of the sphere, and a tricritical point allowing
helical modulations at an arbitrary latitude. We find that instantons (or
skyrmions in two-dimensional Euclidean space) appear as composite solitons in
different fashions in these phases: temporal domain walls or wall-antiwall
pairs (bions) in the easy-axis dominant cases, dislocations (or phase slips)
with fractional instanton numbers in the helical state, and isolated instantons
and calorons living on the top of the helical modulation at the tricritical
point. We also show that the models with DM interaction and an easy-plane
potential can be mapped into those without them, providing a useful tool to
investigate the model with the DM interaction. - Tatsuhiro Misumi; Yuya TanizakiProgress of Theoretical and Experimental Physics Oxford University Press (OUP) 2020 (3) 033B03 2020/03 [Refereed]
Abstract We develop a $(1+1)$D lattice $U(1)$ gauge theory in order to define the two-flavor massless Schwinger model, and discuss its connection with the Haldane conjecture. We propose to use the central-branch Wilson fermion, which is defined by relating the mass, $m$, and the Wilson parameter, $r$, by $m+2r=0$. This setup gives two massless Dirac fermions in the continuum limit, and it turns out that no fine-tuning of $m$ is required because the extra $U(1)$ symmetry at the central branch, $U(1)_{\overline{V } }$, prohibits additive mass renormalization. Moreover, we show that the Dirac determinant is positive semi-definite and this formulation is free from the sign problem, so a Monte Carlo simulation of the path integral is possible. By identifying the symmetry at low energy, we show that this lattice model has a mixed ’t Hooft anomaly between $U(1)_{\overline{V } }$, lattice translation, and lattice rotation. We discuss its relation to the anomaly of half-integer anti-ferromagnetic spin chains, so our lattice gauge theory is suitable for numerical simulation of the Haldane conjecture. Furthermore, it gives a new and strict understanding on the parity-broken phase (Aoki phase) of the $2$D Wilson fermion. - Tatsuhiro Misumi; Toshiaki Fujimori; Etsuko Itou; Muneto Nitta; Norisuke SakaiProceedings of Science SISSA Lattice2019 (015) 2019/12 [Refereed]
We report the results of the lattice simulation of the ${\mathbb C} P^{N-1}$
sigma model on $S_{s}^{1}$(large) $\times$ $S_{\tau}^{1}$(small). We take a
sufficiently large ratio of the circumferences to approximate the model on
${\mathbb R} \times S^1$. For periodic boundary condition imposed in the
$S_{\tau}^{1}$ direction, we show that the expectation value of the Polyakov
loop undergoes a deconfinement crossover as the compactified circumference is
decreased, where the peak of the associated susceptibility gets sharper for
larger $N$. For ${\mathbb Z}_{N}$ twisted boundary condition, we find that,
even at relatively high $\beta$ (small circumference), the regular $N$-sided
polygon-shaped distributions of Polyakov loop leads to small expectation values
of Polyakov loop, which implies unbroken ${\mathbb Z}_{N}$ symmetry if
sufficient statistics and large volumes are adopted. We also argue the
existence of fractional instantons and bions by investigating the dependence of
the Polyakov loop on $S_{s}^{1}$ direction, which causes transition between
${\mathbb Z}_{N}$ vacua. - Toshiaki Fujimori; Etsuko Itou; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPhysical Review D APS 100 (09) 094506 2470-0010 2019/11 [Refereed]
The $\mathbb{C}P^{N-1}$ sigma model at finite temperature is studied using
lattice Monte Carlo simulations on $S_{s}^{1} \times S_{\tau}^{1}$ with radii
$L_{s}$ and $L_{\tau}$, respectively, where the ratio of the circumferences is
taken to be sufficiently large ($L_{s}/L_{\tau} \gg 1$) to simulate the model
on $\mathbb{R} \times S^1$. We show that the expectation value of the Polyakov
loop undergoes a deconfinement crossover as $L_{\tau}$ is decreased, where the
peak of the associated susceptibility gets sharper for larger $N$. We find that
the global PSU($N$)=SU($N$)$/{\mathbb Z}_{N}$ symmetry remains unbroken at
"quantum" and "classical" levels for the small and large $L_{\tau}$,
respectively: in the small $L_\tau$ region for finite $N$, the order parameter
fluctuates extensively with its expectation value consistent with zero after
taking an ensemble average, while in the large $L_\tau$ region the order
parameter remains small with little fluctuations. We also calculate the thermal
entropy and find that the degrees of freedom in the small $L_{\tau}$ regime are
consistent with $N-1$ free complex scalar fields, thereby indicating a good
agreement with the prediction from the large-$N$ study for small $L_{\tau}$. - Tatsuhiro Misumi; Yuya Tanizaki; Mithat ÜnsalJournal of High Energy Physics Springer 2019 (07) 018 2019/07 [Refereed]
This work examines non-perturbative dynamics of a $2$-dimensional QFT by
using discrete 't Hooft anomaly, semi-classics with circle compactification and
bosonization. We focus on charge-$q$ $N$-flavor Schwinger model, and also
Wess-Zumino-Witten model. We first apply the recent developments of discrete 't
Hooft anomaly matching to theories on $\mathbb{R}^2$ and its compactification
to $\mathbb{R} \times S^1_L$. We then compare the 't Hooft anomaly with
dynamics of the models by explicitly constructing eigenstates and calculating
physical quantities on the cylinder spacetime with periodic and flavor-twisted
boundary conditions. We find different boundary conditions realize different
anomalies. Especially under the twisted boundary conditions, there are $Nq$
vacua associated with discrete chiral symmetry breaking. Chiral condensates for
this case have fractional $\theta$ dependence $\mathrm{e}^{\mathrm{i}
\theta/Nq}$, which provides the $Nq$-branch structure with soft fermion mass.
We show that these behaviors at a small circumference cannot be explained by
usual instantons but should be understood by "quantum" instantons, which
saturate the BPS bound between classical action and quantum-induced effective
potential. The effects of the quantum-instantons match the exact results
obtained via bosonization within the region of applicability of semi-classics.
We also argue that large-$N$ limit of the Schwinger model with twisted boundary
conditions satisfy volume independence. - Toshiaki Fujimori; Syo Kamata; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiJournal of High Energy Physics Springer 2019 (02) 190 1029-8479 2019/02 [Refereed]
We derive the semiclassical contributions from the real and complex bions in
the two-dimensional $\mathbb C P^{N-1}$ sigma model on ${\mathbb R} \times S^{1}$ with a twisted boundary condition. The bion configurations are saddle
points of the complexified Euclidean action, which can be viewed as bound
states of a pair of fractional instantons with opposite topological charges. We
first derive the bion solutions by solving the equation of motion in the model
with a potential which simulates an interaction induced by fermions in the
$\mathbb C P^{N-1}$ quantum mechanics. The bion solutions have quasi-moduli
parameters corresponding to the relative distance and phase between the
constituent fractional instantons. By summing over the Kaluza-Klein modes of
the quantum fluctuations around the bion backgrounds, we find that the
effective action for the quasi-moduli parameters is renormalized and becomes a
function of the dynamical scale (or the renormalized coupling constant). Based
on the renormalized effective action, we obtain the semiclassical bion
contribution in a weak coupling limit by making use of the Lefschetz thimble
method. We find that the non-perturbative contribution vanishes in the
supersymmetric case and it has an imaginary ambiguity which is consistent with
the expected infrared renormalon ambiguity in non-supersymmetric cases. This is
the first explicit result indicating the relation between the complex bion and
the infrared renormalon. - Masaru Hongo; Tatsuhiro Misumi; Yuya TanizakiJournal of High Energy Physics Springer 2019 (02) 070 1029-8479 2019/02 [Refereed]
We investigate the phase structure of the compactified $2$-dimensional
nonlinear $SU(3)/U(1)^2$ flag sigma model with respect to two $\theta$-terms.
Based on the circle compactification with the ${\mathbb Z}_{3}$-twisted
boundary condition, which preserves an 't Hooft anomaly of the original
uncompactified theory, we perform the semiclassical analysis based on the
dilute instanton gas approximation (DIGA). We clarify classical vacua of the
theory and derive fractional instanton solutions connecting these vacua. The
resulting phase structure based on DIGA exhibits the quantum phase transitions
and triple degeneracy at special points in the $(\theta_1,\theta_2)$-plane,
which is consistent with the phase diagram obtained from the anomaly matching
and global inconsistency conditions. This result indicates the adiabatic
continuity between the flag sigma models on ${\mathbb R}^{2}$ and ${\mathbb
R}\times S^{1}$ with small compactification radius. We further estimate
contributions from instanton--anti-instanton configuration (bion) and show the
existence of the imaginary ambiguity, which is expected to be cancelled by that
of the perturbative Borel resummation. - Toshiaki Fujimori; Masazumi Honda; Syo Kamata; Tatsuhiro Misumi; Norisuke SakaiProgress of Theoretical and Experimental Physics Oxford academic 2018 (12) 123B03 2018/12 [Refereed]
We study a certain class of supersymmetric (SUSY) observables in 3d
$\mathcal{N}=2$ SUSY Chern-Simons (CS) matter theories and investigate how
their exact results are related to the perturbative series with respect to
coupling constants given by inverse CS levels. We show that the observables
have nontrivial resurgent structures by expressing the exact results as a full
transseries consisting of perturbative and non-perturbative parts. As real mass
parameters are varied, we encounter Stokes phenomena at an infinite number of
points, where the perturbative series becomes non-Borel-summable due to
singularities on the positive real axis of the Borel plane. We also investigate
the Stokes phenomena when the phase of the coupling constant is varied. For
these cases, we find that the Borel ambiguities in the perturbative sector are
canceled by those in nonperturbative sectors and end up with an unambiguous
result which agrees with the exact result even on the Stokes lines. We also
decompose the Coulomb branch localization formula, which is an integral
representation for the exact results, into Lefschetz thimble contributions and
study how they are related to the resurgent transseries. We interpret the
non-perturbative effects appearing in the transseries as contributions of
complexified SUSY solutions which formally satisfy the SUSY conditions but are
not on the original path integral contour. - Yuya Tanizaki; Yuta Kikuchi; Tatsuhiro Misumi; Norisuke SakaiPhysical Review D American Physical Society 97 (5) 054012 2470-0029 2018/03 [Refereed]
We elucidate that the phase diagram of massless N-flavor QCD under a ZN flavor-twisted boundary condition (massless ZN-QCD) is constrained by a 't Hooft anomaly involving two-form gauge fields. As a consequence, massless ZN-QCD turns out to realize persistent order at any temperature and quark chemical potential namely, the symmetric and gapped phase is strictly forbidden. This is the first result on the finite-(T,μ) phase diagram in QCD-type theories based on anomaly matching related to center and discrete axial symmetries. - Yuya Tanizaki; Tatsuhiro Misumi; Norisuke SakaiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2017 (12) 056 1029-8479 2017/12 [Refereed]
Anomaly matching constrains low-energy physics of strongly-coupled field theories, but it is not useful at finite temperature due to contamination from high-energy states. The known exception is an 't Hooft anomaly involving one-form symmetries as in pure SU(N) Yang-Mills theory at theta = pi. Recent development about large-N volume independence, however, gives us a circumstantial evidence that 't Hooft anomalies can also remain under circle compactifications in some theories without one-form symmetries. We develop a systematic procedure for deriving an 't Hooft anomaly of the circle-compactified theory starting from the anomaly of the original uncompactified theory without one-form symmetries, where the twisted boundary condition for the compactified direction plays a pivotal role. As an application, we consider Z(N)-twisted CPN-1 sigma model and massless Z(N)-QCD, and compute their anomalies explicitly. - Tatsuhiro Misumi; Hideo AokiPhysical Review B American Physical Society 96 (15) 155137 2469-9969 2017/10 [Refereed]
We propose a new class of tight-binding models where a flat band exists either gapped from or crossing right through a dispersive band on two-band (i.e., two sites/unit cell) tetragonal and honeycomb lattices. By imposing a condition on the hopping parameters for generic models with up to third-neighbor hoppings, we first obtain models having a rigorously flat band isolated from a dispersive band with a gap, which accommodate both rank reducing and non-rank reducing of the Hamiltonian. The models include Tasaki's flat-band models, but the present model generally has a nonzero flat-band energy whose gap from the dispersive band is controllable as well. We then modify the models by appropriately changing the second- or third-neighbor hoppings, leading to a new class of two-dimensional lattices where a (slightly warped) flat band pierces a dispersive one. As with the known flat-band models, the connectivity condition is satisfied in the present models, so that we have unusual, unorthogonalizable Wannier orbitals. We have also shown that the present flat-band model can be extended to three (or higher) dimensions. Implications on possible high-TC superconductivity are discussed when a repulsive electron-electron interaction is introduced, where the flat band is envisaged to be utilized as intermediate states in pair scattering processes. - Toshiaki Fujimori; Syo Kamata; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS OXFORD UNIV PRESS INC 2017 (8) 083B02 2050-3911 2017/08 [Refereed]
We investigate the resurgence structure in quantum mechanical models originating in 2d nonlinear sigma models with emphasis on nearly supersymmetric and quasi-exactly solvable parameter regimes. By expanding the ground state energy in powers of a supersymmetry-breaking deformation parameter delta is an element of, we derive exact results for the expansion coefficients. In the class of models described by real multiplets, the O(delta is an element of) ground state energy has a non-Borel summable asymptotic series, which gives rise to imaginary ambiguities leading to rich resurgence structure. We discuss sine-Gordon quantum mechanics (QM) as an example and show that the semiclassical contributions from complex multi-bion solutions correctly reproduce the corresponding part in the exact result including the imaginary ambiguities. As a typical model described by chiral multiplets, we discuss CPN-1 QM and show that the exact O(delta is an element of) ground state energy can be completely reconstructed from the semiclassical multi-bion contributions. Although the O(delta is an element of) ground state energy has trivial resurgence structure, a simple but rich resurgence structure appears at O(delta is an element of(2)). We show the complete cancelation between the O(delta is an element of(2)) imaginary ambiguities arising from the non-Borel summable perturbation series and those in the semiclassical contributions of N-1 complex bion solutions. We also discuss the resurgence structure of a squashed CP1 QM. - Toshiaki Fujimori; Syo Kamata; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPHYSICAL REVIEW D AMER PHYSICAL SOC 95 (10) 105001 2470-0010 2017/05 [Refereed]
The full resurgent trans-series is found exactly in near-supersymmetric CP1 quantum mechanics. By expanding in powers of the supersymmetry-breaking deformation parameter, we obtain the first and second expansion coefficients of the ground-state energy. They are an absolutely convergent series of nonperturbative exponentials corresponding to multibions with perturbation series on those backgrounds. We obtain all multibion exact solutions for a finite time interval in the complexified theory. We sum the semiclassical multibion contributions that reproduce the exact result supporting the resurgence to all orders. We also discuss the similar resurgence structure in CPN-1 (N > 2) models. This is the first result in the quantum-mechanical model where the resurgent trans-series structure is verified to all orders in nonperturbative multibion contributions. - Syo Kamata; So Matsuura; Tatsuhiro Misumi; Kazutoshi OhtaProceedings of Science SISSA Lattice2016 (210) 2016/12 [Refereed]
We perform a numerical simulation of the two-dimensional ${\cal N}=(2,2)$
supersymmetric Yang-Mills (SYM) theory on the discretized curved space. The
$U(1)_{A}$ anomaly of the continuum theory is maintained also in the
discretized theory as an unbalance of the number of the fermions. In the
process, we propose a new phase-quenched approximation, which we call the
"anomaly-phase-quenched (APQ) method", to make the partition function and
observables well-defined by $U(1)_{A}$ phase cancellation. By adopting APQ
method, we estimate the Ward-Takahashi identity for exact SUSY on lattice and
clarify contribution of the pseudo zero-modes to the pfaffian phase. - Syo Kamata; So Matsuura; Tatsuhiro Misumi; Kazutoshi OhtaPROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS OXFORD UNIV PRESS INC 2016 (12) 123B01 2050-3911 2016/12 [Refereed]
We investigate two-dimensional N = (2, 2) supersymmetric Yang-Mills (SYM) theory on discretized curved space (polyhedra). We first revisit that the number of supersymmetries of the continuum N = (2, 2) SYM theory on any curved manifold can be enhanced at least to two by introducing an appropriate U(1) gauge background associated with the U(1)(V) symmetry. We then show that the generalized Sugino model on discretized curved space, which was proposed in our previous work, can be identified with the discretization of this SUSY enhanced theory, where one of the supersymmetries remains, and the other is broken but restored in the continuum limit. We find that the U(1)(A) anomaly exists also in discretized theory as a result of an unbalance in the number of fermions proportional to the Euler characteristic of the polyhedra. We then study this model by using the numerical Monte Carlo simulation. We propose a novel phase-quench method called the "anomaly-phase-quenched approximation" with respect to the U(1)(A) anomaly. We show numerically that the Ward-Takahashi identity associated with the remaining supersymmetry is realized by adopting this approximation. We work out the relation between the sign (phase) problem and pseudo-zero-modes of the Dirac operator. We also show that the divergent behavior of the scalar one-point function gets milder as the genus of the background increases. These are the first numerical observations for the supersymmetric lattice model on curved space with generic topologies. - Toshiaki Fujimori; Syo Kamata; Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPHYSICAL REVIEW D AMER PHYSICAL SOC 94 (10) 105002 2470-0010 2016/11 [Refereed]
We discuss the nonperturbative contributions from real and complex saddle point solutions in the CP1 quantum mechanics with fermionic degrees of freedom, using the Lefschetz thimble formalism beyond the Gaussian approximation. We find bion solutions, which correspond to (complexified) instanton-anti-instanton configurations stabilized in the presence of the fermionic degrees of freedom. By computing the one-loop determinants in the bion backgrounds, we obtain the leading order contributions from both the real and complex bion solutions. To incorporate quasizero modes which become nearly massless in a weak coupling limit, we regard the bion solutions as well-separated instanton-anti-instanton configurations and calculate a complexified quasimoduli integral based on the Lefschetz thimble formalism. The nonperturbative contributions from the real and complex bions are shown to cancel out in the supersymmetric case and give an (expected) ambiguity in the nonsupersymmetric case, which plays a vital role in the resurgent trans-series. For nearly supersymmetric situations, evaluation of the Lefschetz thimble gives results in precise agreement with those of the direct evaluation of the Schrodinger equation. We also perform the same analysis for the sine-Gordon quantum mechanics and point out some important differences showing that the sine-Gordon quantum mechanics does not correctly describe the 1d limit of the CPN-1 field theory of R x S-1. - Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2016 (5) 057 1029-8479 2016/05 [Refereed]
We investigate non-BPS exact solutions in CPN-1 sigma models on R-1 x S-1 with twisted boundary conditions, by using the Din-Zakrzewski projection method. We focus on the relation of the non-BPS solutions to the ansatz of multi-instanton (bion) configurations and discuss their significance in the context of the resurgence theory. We find that the transition between seemingly distinct configurations of multi-instantons occur as moduli changes in the non-BPS solutions, and the simplest non-BPS exact solution corresponds to multi-bion configurations with fully-compressed double fractional instantons in the middle. It indicates that the non-BPS solutions make small but nonzero contribution to the resurgent trans-series as special cases of the multi-bion configurations. We observe a generic pattern of transitions between distinct multi-bion configurations (flipping partners), leading to the three essential properties of the non-BPS exact solution: (i) opposite sign for terms corresponding to the left and right infinities, (ii) symmetric location of fractional instantons, and (iii) the transition between distinct bion configurations. By studying the balance of forces, we show that the relative phases between the instanton constituents play decisive roles in stability and instability of the muli-instanton configurations. We discuss local and global instabilities of the solutions such as negative modes and the flow to the other saddle points, by considering the deformations of the non-BPS exact solutions within our multi-instanton ansatz. We also briefly discuss some classes of the non-BPS exact solutions in Grassmann sigma models. - Hiroaki Kouno; Kouji Kashiwa; Junichi Takahashi; Tatsuhiro Misumi; Masanobu YahiroPHYSICAL REVIEW D AMER PHYSICAL SOC 93 (5) 056009 2470-0010 2016/03 [Refereed]
We investigate QCD at large mu/T by using Z(3)-symmetric SU(3) gauge theory, where mu is the quark-number chemical potential and T is temperature. We impose the flavor-dependent twist boundary condition on quarks in QCD. This QCD-like theory has the twist angle theta as a parameter, and agrees with QCD when theta = 0 and becomes symmetric when theta = 2 pi/3. For both QCD and the Z(3)-symmetric SU(3) gauge theory, the phase diagram is drawn in mu-T plane with the Polyakov-loop extended Nambu-Jona-Lasinio model. In the Z(3)-symmetric SU(3) gauge theory, the Polyakov loop phi is zero in the confined phase appearing at T less than or similar to 200 MeV and mu less than or similar to 300 MeV. The perfectly confined phase never coexists with the color superconducting (CSC) phase, since finite diquark condensate in the CSC phase breaks Z(3) symmetry and then makes f finite phi When mu greater than or similar to 300 MeV, the CSC phase is more stable than the perfectly confined phase at T less than or similar to 100 MeV. Meanwhile, the chiral symmetry can be broken in the perfectly confined phase, since the chiral condensate is Z(3) invariant. Consequently, the perfectly confined phase is divided into the perfectly confined phase without chiral symmetry restoration in a region of mu less than or similar to 300 MeV and T less than or similar to 200 MeV and the perfectly confined phase with chiral symmetry restoration in a region of mu greater than or similar to 300 MeV and 100 less than or similar to T less than or similar to 200 MeV. At low temperature, the basic phase structure of Z(3)-symmetric QCD-like theory remains in QCD. Properties of the sign problem in Z(3)-symmetric theory are also discussed. We discuss a numerical framework to evaluate observables at theta = 0 from those at theta = 2 pi/3. - Takumi Iritani; Etsuko Itou; Tatsuhiro MisumiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2015 (11) 159 1029-8479 2015/11 [Refereed]
We investigate QCD-like theory with exact center symmetry, with emphasis on the finite-temperature phase transition concerning center and chiral symmetries. On the lattice, we formulate center symmetric SU(3) gauge theory with three fundamental Wilson quarks by twisting quark boundary conditions in a compact direction (Z(3)-QCD model). We calculate the expectation value of Polyakov loop and the chiral condensate as a function of temperature on 16(3) x 4 and 20(3) x 4 lattices along the line of constant physics realizing m(PS)/m(V) = 0.70. We find out the first-order center phase transition, where the hysteresis of the magnitude of Polyakov loop exists depending on thermalization processes. We show that chiral condensate decreases around the critical temperature in a similar way to that of the standard three-flavor QCD, as it has the hysteresis in the same range as that of Polyakov loop. We also show that the flavor symmetry breaking due to the twisted boundary condition gets qualitatively manifest in the high-temperature phase. These results are consistent with the predictions based on the chiral effective model in the literature. Our approach could provide novel insights to the nonperturbative connection between the center and chiral properties. - Tatsuhiro Misumi; Takumi Iritani; Etsuko ItouProceedings of Science SISSA Lattice2015 (152) 2015/10 [Refereed]
For the $Z_{3}$-symmetric lattice QCD-like theory ($Z_3$-QCD), in which
$SU(3)$ gauge theory is coupled with three fundamental Wilson quarks with
flavor-dependent twisted boundary conditions, we calculate the expectation
values of Polyakov loop and chiral condensate as functions of temperature on
$16^3 \times4$ and $20^3 \times 4$ lattices with $m_{PS}/m_{V}=0.70$ fixed. We
find the first-order phase transition with respect to the $Z_{3}$ center
symmetry, where the Polyakov loop exhibits a hysteresis depending on the
initial condition of thermalization process. We also show that the crossover
behavior of chiral condensate around the critical temperature of the center
transition and the manifestation of flavor symmetry breaking in the
high-temperature phase. - Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2015 (9) 157 1029-8479 2015/09 [Refereed]
We compute multi-instanton amplitudes in the sine-Gordon quantum mechanics (periodic cosine potential) by integrating out quasi-moduli parameters corresponding to separations of instantons and anti-instantons. We propose an extension of Bogomolnyi-Zinn-Justin prescription for multi-instanton configurations and an appropriate subtraction scheme. We obtain the multi-instanton contributions to the energy eigenvalue of the lowest band at the zeroth order of the coupling constant. For the configurations with only instantons (anti-instantons), we obtain unambiguous results. For those with both instantons and anti-instantons, we obtain results with imaginary parts, which depend on the path of analytic continuation. We show that the imaginary parts of the multi-instanton amplitudes precisely cancel the imaginary parts of the Borel resummation of the perturbation series, and verify that our results completely agree with those based on the uniform-WKB calculations, thus confirming the resurgence structure: divergent perturbation series combined with the nonperturbative multi-instanton contributions conspire to give unambiguous results. We also study the neutral bion contributions in the CPN-1 model on R-1 x S-1 with a small circumference, taking account of the relative phase moduli between the fractional instanton and anti-instanton. We find that the sign of the interaction potential depends on the relative phase moduli, and that both the real and imaginary parts resulting from quasi-moduli integral of the neutral bion get quantitative corrections compared to the sine-Gordon quantum mechanics. - Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiPROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS OXFORD UNIV PRESS INC 2015 (3) 033B02 2050-3911 2015/03 [Refereed]
We classify bions in the Grassmann Gr(NF),(NC) sigma model (including the CPNF-1 model) on R-1 x S-1 with twisted boundary conditions. We formulate these models as U(N-C) gauge theories with N-F flavors in the fundamental representations. These theories can be promoted to supersymmetric gauge theories and, further, can be embedded into D-brane configurations in type-II superstring theories. We focus on specific configurations composed of multiple fractional instantons, termed neutral bions and charged bions, which are identified as perturbative infrared renormalons by Unsal and his collaborators [G. V. Dunne and M. Unsal, J. High Energy Phys. 1211, 170 (2012); G. V. Dunne and M. Unsal, Phys. Rev. D 87, 025015 (2013)]. We show that D-brane configurations, as well as the moduli matrix, offer a very useful tool to classify all possible bion configurations in these models. In contrast to the CPNF-1 model, there exist Bogomol'nyi-Prasad-Sommerfield (BPS) fractional instantons with topological charges greater than unity (of order N-C) that cannot be reduced to a composite of an instanton and fractional instantons. As a consequence, we find that the Grassmann sigma model admits neutral bions made of BPS and anti-BPS fractional instantons, each of which has a topological charge greater (less) than one (minus one), that are not decomposable into an instanton-anti-instanton pair and the rest. The CPNF-1 model is found to have no charged bions. In contrast, we find that the Grassmann sigma model admits charged bions, for which we construct exact non-BPS solutions of the field equations. - So Matsuura; Tatsuhiro Misumi; Kazutoshi OhtaProgress of Theoretical and Experimental Physics OXFORD UNIV PRESS INC 2015 (3) 033B07 2050-3911 2015/03 [Refereed]
We apply the localization technique to topologically twisted N = (2, 2) supersymmetric gauge theory on a discretized Riemann surface (the generalized Sugino model). We exactly evaluate the partition function and the vacuum expectation value (vev) of a specific Q-closed operator. We show that both the partition function and the vev of the operator depend only on the Euler characteristic and the area of the discretized Riemann surface and are independent of the details of the discretization. This localization technique may not only simplify the numerical analysis of supersymmetric lattice models but also connect the well defined equivariant localization to the empirical supersymmetric localization. - Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiXXXTH INTERNATIONAL COLLOQUIUM ON GROUP THEORETICAL METHODS IN PHYSICS (ICGTMP) (GROUP30) IOP PUBLISHING LTD 597 (01) 012060 1742-6588 2015 [Refereed]
Classical configurations in the CPN-1 model on R-1 x S-1 is studied with twisted boundary conditions. Starting from fractional instantons with the Z(N) twisted boundary conditions, we review briefly the relevance of our study to resurgence phenomenon in field theory. We consider primarily configurations composed of multiple fractional instantons, called "neutral bions", which are identified as "perturbative infrared renormalons". We construct an explicit ansatz corresponding to topologically trivial configurations containing one fractional instanton (nu = 1/N) and one fractional anti-instanton (nu = -1/N), which is guaranteed to become a solution of field equations asymptotically for large separations. The attractive interactions between the instanton constituents from small to large separations are found to be consistent with the standard separated-instanton calculus. Our results suggest that the ansatz enables us to study bions and the related physics for a wide range of separations. This talk is mainly based on our recent work published in JHEP 1406, 164 (2014) [arXiv:1404.7225 [hep-th]]. - So Matsuura; Tatsuhiro Misumi; Kazutoshi OhtaPROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS OXFORD UNIV PRESS INC 2014 (12) 123B01 2050-3911 2014/12 [Refereed]
We define supersymmetric Yang-Mills theory on an arbitrary 2D lattice (polygon decomposition) while preserving one supercharge. When a smooth Riemann surface Sigma(g) with genus g emerges as an appropriate continuum limit of the generic lattice, the discretized theory becomes a topologically twisted N = (2, 2) supersymmetric Yang-Mills theory on Sigma(g). If we adopt the usual square lattice as a special case of the discretization, our formulation is identical with Sugino's lattice model. Although the tuning of parameters is generally required while taking the continuum limit, the number of necessary parameters is at most two because of the gauge symmetry and the supersymmetry. In particular, we do not need any fine-tuning if we arrange the theory so as to possess an extra global U(1) symmetry (U(1)(R) symmetry), which rotates the scalar fields. - Tatsuhiro Misumi; Muneto Nitta; Norisuke SakaiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2014 (6) 164 1029-8479 2014/06 [Refereed]
We study classical configurations in the CPN -1 model on R-1 x S-1 with twisted boundary conditions. We focus on specific configurations composed of multiple fractionalized-instantons, termed "neutral bions", which are identified as "perturbative infrared renormalons" by Unsal and his collaborators. For Z(N) twisted boundary conditions, we consider an explicit ansatz corresponding to topologically trivial configurations containing one fractionalized instanton (nu = 1/N) and one fractionalized anti-instanton (nu = -1/N) at large separations, and exhibit the attractive interaction between the instanton constituents and how they behave at shorter separations. We show that the bosonic interaction potential between the constituents as a function of both the separation and N is consistent with the standard separated-instanton calculus even from short to large separations, which indicates that the ansatz enables us to study bions and the related physics for a wide range of separations. We also propose different bion ansatze in a certain non-Z(N) twisted boundary condition corresponding to the "split" vacuum for N = 3 and its extensions for N >= 3. We find that the interaction potential has qualitatively the same asymptotic behavior and N-dependence as those of bions for Z(N) twisted boundary conditions. - Tatsuhiro Misumi; Takuya KanazawaJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2014 (6) 181 1029-8479 2014/06 [Refereed]
We investigate QCD with adjoint Dirac fermions on R-3 x S-1 with generic boundary conditions for fermions along S-1. By means of perturbation theory, semiclassical methods and a chiral effective model, we elucidate a rich phase structure in the space spanned by the S-1 compactification scale L, twisted fermionic boundary condition phi and the fermion mass m. We found various phases with or without chiral and center symmetry breaking, separated by first- and second-order phase transitions, which in specific limits (phi = 0, phi = pi, L --> 0 and m --> infinity) reproduce known results in the literature. In the center-symmetric phase at small L, we show that Unsal's bion-induced confinement mechanism is at work but is substantially weakened at phi not equal 0 by a linear potential between monopoles. Through an analytic and numerical study of the PNJL model, we show that the order parameters for center and chiral symmetries (i.e., Polyakov loop and chiral condensate) are strongly intertwined at phi not equal 0. Due to this correlation, a deconfined phase can intervene between a weak-coupling center-symmetric phase at small L and a strong-coupling one at large L. Whether this happens or not depends on the ratio of the dynamical fermion mass to the energy scale of the Yang-Mills theory. Implication of this possibility for resurgence in gauge theories is briefly discussed. In an appendix, we study the index of the adjoint Dirac operator on R-3 x S-1 with twisted boundary conditions, which is important for semiclassical analysis of monopoles. - Kouji Kashiwa; Hiroaki Kouno; Takahiro Makiyama; Tatsuhiro Misumi; Takahiro Sasaki; Masanobu YahiroProceedings of Scieince, Lattice2013 SISSA 101 2013/12 [Refereed]
We investigated the phase diagram of $SU(3)$ gauge theory in four dimension
with one compact dimension by using the perturbative one-loop effective
potential. Effects of the adjoint and fundamental fermions are investigated and
then the rich phase structure in the quark-mass and compact-size scale is
realized. Our results are qualitatively consistent with the recent lattice
calculation and clearly show that the lattice calculation can be understood
from the Hosotani mechanism. Moreover, we show the result obtained by using the
flavor twisted boundary condition for fundamental fermion which does not break
the $Z_3$ symmetry, explicitly. - Tatsuhiro MisumiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2013 (12) 063 1029-8479 2013/12 [Refereed]
We revisit 2D = (2, 2) super Yang-Mills lattice formulation (Sugino model) to investigate its fermion action with two (Majorana) fermion flavors and exact chiral-U(1) (R) symmetry. We show that the reconcilement of chiral symmetry and absence of further species-doubling originates in the 4D clifford algebra structure of the action, where 2D two flavors are spuriously treated as a single 4D four-spinor with four 4D gamma matrices introduced into kinetic and Wilson terms. This fermion construction based on the higher-dimensional clifford algebra is extended to four dimensions in two manners: (1) pseudo-8D sixteen-spinor treatment of 4D four flavors with eight 8D gamma matrices, (2) pseudo-6D eight-spinor treatment of 4D two flavors with five out of six 6D gamma matrices. We obtain 4D four-species and two-species lattice fermions with unbroken subgroup of chiral symmetry and other essential properties. We discuss their relations to staggered and Wilson twisted-mass fermions. We also discuss their potential feedback to 4D super Yang-Mills lattice formulations. - Hiroaki Kouno; Tatsuhiro Misumi; Kouji Kashiwa; Takahiro Makiyama; Takahiro Sasaki; Masanobu YahiroPHYSICAL REVIEW D AMER PHYSICAL SOC 88 (1) 016002 1550-7998 2013/07 [Refereed]
We investigate differences and similarities between fundamental fermions and adjoint fermions in SU(N) gauge theory. The gauge theory with fundamental fermions possesses Z(N) symmetry only in the limit of infinite fermion mass, whereas the gauge theory with adjoint fermions does have the symmetry for any fermion mass. The flavor-dependent twisted boundary condition (FTBC) is then imposed on fundamental fermions so that the theory with fundamental fermions can possess Z(N) symmetry for any fermion mass. We show similarities between FTBC fundamental fermions and adjoint fermions, using the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. In the mean-field level, the PNJL model with FTBC fundamental fermions has dynamics similar to the PNJL model with adjoint fermions for the confinement-deconfinement transition related to Z(N) symmetry. The chiral property is somewhat different between the two models, but there is a simple relation between chiral condensates in the two models. As an interesting high-energy phenomenon, a possibility of the gauge symmetry breaking is studied for FTBC fundamental fermions. - Kouji Kashiwa; Tatsuhiro MisumiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2013 (5) 042 1029-8479 2013/05 [Refereed]
We investigate the phase structure of SU(3) gauge theory in four and five dimensions with one compact dimension by using perturbative one-loop and PNJL-model-based effective potentials, with emphasis on spontaneous gauge symmetry breaking. When adjoint matter with the periodic boundary condition is introduced, we have rich phase structure in the quark-mass and compact-size space with gauge-symmetry-broken phases, called the SU(2) x U(1) split and the U(1) x U(1) re-confined phases. Our result is qualitatively consistent with the recent lattice calculations. When fundamental quarks are introduced in addition to adjoint quarks, the split phase becomes more dominant and larger as a result of explicit center symmetry breaking. We also show that another U(1) x U(1) phase (pseudo-reconfined phase) with negative vacuum expectation value of Polyakov loop exists in this case. We study chiral properties in these theories and show that chiral condensate gradually decreases and chiral symmetry is slowly restored as the size of the compact dimension is decreased. - Tatsuhiro Misumi; Taro Kimura; Akira OhnishiPHYSICAL REVIEW D AMER PHYSICAL SOC 86 (9) 094505 1550-7998 2012/11 [Refereed]
We propose a new framework for investigating two-flavor lattice QCD with finite temperature and density. We consider the Karsten-Wilczek fermion formulation, in which a species-dependent imaginary chemical potential term can reduce the number of species to two without losing chiral symmetry. This lattice discretization is useful for study on finite-(T; mu) QCD since its discrete symmetries are appropriate for the case. To show its applicability, we study strong-coupling lattice QCD with temperature and chemical potential. We derive the effective potential of the scalar meson field and obtain a critical line of the chiral phase transition, which is qualitatively consistent with the phenomenologically expected phase diagram. We also discuss that O(1/a) renormalization of imaginary chemical potential can be controlled by adjusting a parameter of a dimension-3 counterterm. - Tatsuhiro MisumiProceedings of Science, Lattice2012 SISSA 005 2012/11 [Refereed][Invited]
We review the recent progress in new lattice fermion formulations. We focus
on the following three types which have possibility of improving lattice
simulations. (1) Flavored-mass fermions are a generalization of Wilson fermions
with species-splitting mass terms. In particular, staggered-Wilson fermions
initiated by Adams have possibilities of reducing numerical costs in overlap
fermions and the influence of taste-breaking in staggered fermions. (2)
Central-branch Wilson fermions, in which additive mass renormalization is
forbidden by extra axial symmetry, could enable us to perform Wilson-... - Takashi Z. Nakano; Tatsuhiro Misumi; Taro Kimura; Akira OhnishiProceedings of Science, Lattice2012 SISSA 203 2012/10 [Refereed]
We study strong-coupling lattice QCD with staggered-Wilson fermions, with an
emphasis on the possibility of spontaneous parity breaking. We perform
effective potential analysis in the strong-coupling limit. From gap equations
we find the pion condensate becomes nonzero in some range of a mass parameter,
which indicates the existence of the parity-broken phase. We also find massless
pions and PCAC relations around the second-order phase boundary. These results
suggest that we can take the chiral limit by tuning a mass parameter in lattice
QCD with staggered-Wilson fermions as with the Wilson... - Taro Kimura; Tatsuhiro Misumi; Akira OhnishiProceedings of Science, Lattice2012 SISSA 079 2012/10 [Refereed]
We propose a new framework for investigating two-flavor lattice QCD with
finite temperature and density by applying the Karsten-Wilczek lattice fermion,
in which a species-dependent imaginary chemical potential can reduce the number
of species to two without losing chiral symmetry. This lattice discretization
is useful for study on finite-(T,\mu) QCD since its discrete symmetries are
appropriate for the case. To show its applicability, we study strong-coupling
lattice QCD with temperature and chemical potential. We derive the effective
potential of the scalar meson field and obtain a critic... - Tatsuhiro MisumiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2012 (8) 068 1029-8479 2012/08 [Refereed]
We discuss the chiral phase diagram in the parameter space of lattice QCD with minimal-doubling fermions, which can be seen as lattice fermions with flavored chemical potential terms. We study strong-coupling lattice QCD with the Karsten-Wilczek formulation, which has one relevant parameter mu(3) as well as gauge coupling and a mass parameter. We find a nontrivial chiral phase structure with a second-order phase transition between chiral symmetric and broken phases. To capture the whole structure of the phase diagram, we study the related lattice Gross-Neveu model. The result indicates that the chiral phase transition also exists in the weak-coupling region. From these results we speculate on the mu(3)-g(2) chiral phase diagram in lattice QCD with minimal-doubling fermions, and discuss their application to numerical simulations. - Tatsuhiro Misumi; Takashi Z. Nakano; Taro Kimura; Akira OhnishiPHYSICAL REVIEW D AMER PHYSICAL SOC 86 (3) 03 - 034501 1550-7998 2012/08 [Refereed]
We study strong-coupling lattice QCD with staggered-Wilson fermions, with an emphasis on discrete symmetries and the possibility of their spontaneous breaking. We perform hopping parameter expansion and effective potential analyses in the strong-coupling limit. From gap equations we find the nonzero pion condensate in some range of a mass parameter, which indicates the existence of the parity-broken phase in lattice QCD with staggered-Wilson fermions. We also find massless pions and PCAC relations around the second-order phase boundary. These results suggest that we can take a chiral limit by tuning a mass parameter in lattice QCD with staggered-Wilson fermions as we would with the Wilson fermion. - Taro Kimura; Shota Komatsu; Tatsuhiro Misumi; Toshifumi Noumi; Shingo Torii; Sinya AokiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2012 (1) 048 1029-8479 2012/01 [Refereed]
Employing the spin-flavor representation, we investigate the structures of the doubler-mixing symmetries and the mechanisms of their spontaneous breakdown in four types of lattice fermion formulation. We first revisit the U(4) x U(4) symmetries of the naive fermion with the vanishing bare mass m, and re-express them in terms of the spin-flavor representation. We apply the same method to the Wilson fermion, which possesses only the U(1) vector symmetry for general values of m. For a special value of m, however, there emerges an additional U(1) symmetry to be broken by pion condensation. We also explore two types of minimally doubled fermion, and discover a similar kind of symmetry enhancement and its spontaneous breakdown. - Tatsuhiro Misumi; Michael Creutz; Taro Kimura; Takashi Z. Nakano; Akira OhnishiProceedings of Science, Lattice2011 SISSA 108 2011/10 [Refereed]
We investigate the parity-broken phase (Aoki phase) for staggered-Wilson
fermions by using the Gross-Neveu model and the strong-coupling lattice QCD. In
the both cases the gap equations indicate the parity-broken phase exists and
the pion becomes massless on the phase boundaries. We also show we can take the
chiral and continuum limit in the Gross-Neveu model by tuning mass and
gauge-coupling parameters. This supports the idea that the staggered-Wilson
fermions can be applied to the lattice QCD simulation by taking a chiral limit,
as with Wilson fermions. - Taro Kimura; Michael Creutz; Tatsuhiro MisumiProceedings of Science, Lattice2011 SISSA 106 2011/10 [Refereed]
We present a theoretical foundation for the index theorem in naive and
minimally doubled lattice fermions by studying the spectral flow of a Hermitean
version of Dirac operators. We utilize the point splitting method to implement
flavored mass terms, which play an important role in constructing proper
Hermitean operators. We show the spectral flow correctly detects the index of
the would-be zero modes which is determined by gauge field topology and the
number of species doublers. Using the flavored mass terms, we present new types
of overlap fermions from the naive fermion kernels, with a n... - Michael Creutz; Taro Kimura; Tatsuhiro MisumiPHYSICAL REVIEW D AMER PHYSICAL SOC 83 (9) 094506 1550-7998 2011/05 [Refereed]
We investigate the parity-broken phase structure for staggered and naive fermions in the Gross-Neveu model as a toy model of QCD. We consider a generalized staggered Gross-Neveu model including two types of four-point interactions. We use generalized mass terms to split the doublers for both staggered and naive fermions. The phase boundaries derived from the gap equations show that the mass splitting of tastes results in an Aoki phase both in the staggered and naive cases. We also discuss the continuum limit of these models and explore taking the chirally symmetric limit by fine-tuning a mass parameter and two-coupling constants. This supports the idea that in lattice QCD we can derive one- or two-flavor staggered fermions by tuning the mass parameter, which are likely to be less expensive than Wilson fermions in QCD simulation. - Michael Creutz; Taro Kimura; Tatsuhiro MisumiJOURNAL OF HIGH ENERGY PHYSICS SPRINGER 2010 (12) 041 1029-8479 2010/12 [Refereed]
We present a theoretical foundation for the Index theorem in naive and minimally doubled lattice fermions by studying the spectral flow of a Hermitean version of Dirac operators. We utilize the point splitting method to implement flavored mass terms, which play an important role in constructing proper Hermitean operators. We show the spectral flow correctly detects the index of the would-be zero modes which is determined by gauge field topology. Using the flavored mass terms, we present new types of overlap fermions from the naive fermion kernels, with a number of flavors that depends on the choice of the mass terms. We succeed to obtain a single-flavor naive overlap fermion which maintains hypercubic symmetry. - Michael Creutz; Tatsuhiro MisumiPHYSICAL REVIEW D AMER PHYSICAL SOC 82 (7) 074502 1550-7998 2010/10 [Refereed]
We propose a method to control the number of species of lattice fermions, which yields new classes of minimally doubled lattice fermions. We show it is possible to control the number of species by handling O(a) Wilson-term-like corrections in fermion actions, which we will term "twisted-ordering method". Using this method we obtain new minimally doubled actions with one exact chiral symmetry and exact locality. We classify the known minimally doubled fermions into two types based on the locations of the propagator poles in the Brillouin zone. - Tatsuhiro Misumi; Michael Creutz; Taro KimuraProceedings of Science, Lattice2010 SISSA 260 2010/10 [Refereed]
We propose a method to control the number of species of lattice fermions,
which yields new classes of minimally doubled lattice fermions with one exact
chiral symmetry and exact locality. We classify all the known minimally doubled
fermions into two types based on the locations of the propagator poles in the
Brillouin zone. We also study higher-dimensional extension of them and show it
tends to be more difficult to realize minimal-doubling in higher dimensions. - Taro Kimura; Tatsuhiro MisumiPROGRESS OF THEORETICAL PHYSICS PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE 124 (3) 415 - 432 0033-068X 2010/09 [Refereed]
We study minimal-doubling fermion actions on hyperdiamond and deformed-hyperdiamond lattices, with emphasis on the real-space construction of them and Lorentz covariance of excitations from fermion poles. We propose the improved spatial construction of Creutz fermion action on a deformed hyperdiamond lattice, and discuss conditions for a hyperdiamond-lattice action to produce Lorentz-covariant excitations from poles of fermion propagators. It is pointed out that the non-nearest-site hoppings are essential for the correct excitations. We also propose a class of minimal-doubling actions defined on a deformed hypercubic lattice as a generalization of Creutz-type actions. In addition we introduce a two-parameter class of Wilczek-type minimal-doubling actions. - Mitsutoshi Fujita; Toru Kikuchi; Kenji Fukushima; Tatsuhiro Misumi; Masaki MuratakPHYSICAL REVIEW D AMER PHYSICAL SOC 81 (6) 065024 1550-7998 2010/03 [Refereed]
We investigate the finite-temperature spectral functions of heavy quarkonia by using the soft-wall antide Sitter/QCD model. We discuss the scalar, the pseudoscalar, the vector, and the axial-vector mesons and compare their qualitative features of the melting temperature and growing width. We find that the axial-vector meson melts earlier than the vector meson, while there appears only a slight difference between the scalar and pseudoscalar mesons, which also melt earlier than the vector meson. - Taro Kimura; Tatsuhiro MisumiPROGRESS OF THEORETICAL PHYSICS PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE 123 (1) 63 - 78 0033-068X 2010/01 [Refereed]
In this paper we generalize to higher dimensions several types of fermion actions on the hyperdiamond lattice including a two-parameter class of minimal-doubling fermions "Creutz fermion" and a simple fermion with sufficient discrete symmetry "BBTW fermion". Then it is shown that they possess some properties in common with the four-dimensional case: BBTW fermions in higher even dimensions inevitably yield unphysical degrees of freedom. Creutz fermions are defined oil the distorted lattices, and they lose the high discrete symmetry of the original lattices. We also find properties specific to the higher-dimensional cases. The parameter range for Creutz action to yield minimal-doubling and physical fermions becomes narrower with the dimension getting higher; and thus it becomes more and more difficult to realize minimal-doubling. In addition, we generalize the subspecies of Creutz and BBTW actions including a new class of minimal-doubling actions "Appended Creutz action". - Mitsutoshi Fujita; Kenji Fukushima; Tatsuhiro Misumi; Masaki MurataPHYSICAL REVIEW D AMER PHYSICAL SOC 80 (3) 035001 1550-7998 2009/08 [Refereed]
We use the soft-wall anti-de Sitter/QCD model to investigate the finite-temperature effects on the spectral function in the vector channel. The dissociation of the vector meson tower onto the anti-de Sitter black hole leads to the in-medium mass shift and the width broadening in a way similar to the lattice QCD results for the heavy quarkonium at finite temperature. We also show the momentum dependence of the spectral function and find it consistent with screening in a hot wind. - T. Misumi; K. ShizuyaPHYSICAL REVIEW B AMER PHYSICAL SOC 77 (19) 195423 1098-0121 2008/05 [Refereed]
The electromagnetic response of bilayer graphene in a magnetic field is studied in comparison to that of monolayer graphene. Both types of graphene turn out to be qualitatively quite similar in dielectric and screening characteristics, especially those deriving from vacuum fluctuations, but the effect is generally much more sizable for bilayers. The presence of the zero-(energy-)mode Landau levels is a feature specific to graphene. In bilayers, unlike in monolayers, the effect of the zero-mode levels becomes visible and even dominant in density response as an externally controllable band gap develops. It is pointed out that the splitting of nearly degenerate pseudo-zero-mode levels at each valley, which are specific to bilayer graphene, is controlled by an applied inplane electric field or by an injected current. In addition, a low-energy effective gauge theory of bilayer graphene is constructed.
Books etc
- Quantum mechanicsTatsuhiro MISUMI (Single work)saiensu-sha 2023/04 9784781915708
- MISUMI Tatsuhiro (Single work)Saiensu-sha 2019/12
- Resurgence theory: understanding nonperturbative effects from perturbation theoryFUJIMORI Toshiaki; MISUMI Tatsuhiro; SAKAI Norisuke (Joint work)JPS 2018/06
- Divergence in Perturbative Expansion and Non-perturbative Quantum EffectsMISUMI Tatsuhiro (Single work)Saiensu-sha 2016/08
Conference Activities & Talks
- More on resurgence in quantum theory [Invited]Tatsuhiro MISUMISISSA Theoretical Particle Group Seminar 2024/03 Trieste SISSA
We investigate the resurgent structure of quantum theory, with emphasis on IR-renormalon, phase transition and quantization condition. (1)We first study the 2D sigma models at large N. We show that the renormalon imaginary ambiguity is cancelled by the combined imaginary ambiguities at the different orders of the trans- series. (2)We secondly discuss the nontrivial relation between phase transition and Borel singularities. We show the order of phase transition in some QFT can be understood by studying the details of collision of Borel singularities. (3)We thirdly discuss the application of Exact-WKB to a variety of quantum-mechanical systems. In particular, a generic quantization condition for QM describing a particle on S1 is derived by use of Exact-WKB. - Tatsuhiro MISUMIKEK Theory Workshop 2023 2023/11 Tsukuba KEK
Since the establishment of the Standard Model of elementary particles, the research in quantum field theory has investigated non-perturbative analysis based on theories with high symmetry, such as supersymmetry. However, the Standard Model, including QCD, has relatively low symmetry, and it is getting important to analyze theories based on features appearing only in QFT with low symmetry. In this talk, I will introduce resurgence theory and graph-based lattice field theory as directions for non-perturbative understanding of QFT that does not rely on symmetry, and will provide a guideline for future research on QFT. - Tatsuhiro MISUMISupersymmetry, Soliton and Resurgence 2023/08 Meguro, Tokyo TIT
- Resurgence in quantum field theory [Invited]Tatsuhiro MISUMIInvitation to Recursion, Resurgence and Combinatorics 2023/04 OIST OIST
- Tatsuhiro MISUMINovel Lattice Fermions and their Suitability for High-Performance Computing and Perturbation Theory 2023/03 Mainz Mainz University, MITP
- Tatsuhiro MISUMIApplicable resurgent asymptotics: Summary meeting(AR2W03) 2022/12 UK Newton Institute, the university of cambridge
- Tatsuhiro MISUMITheoretical Particle Group Seminar at Osaka U. 2022/10
- Introduction to Resurgence theory [Invited]Tatsuhiro MISUMILecture at Ibaraki University 2022/08
- Reflection on lattice fermions [Invited]三角樹弘格子上の場の理論と連続空間上の場の理論 2022/07 Kyoto 京都大学基礎物理学研究所，理研iTHEMS
この講演では，既知のものを含む格子フェルミオン定式化のさまざまな手法を概説した後，格子フェルミオンがグラフ理論におけるspectral graphとして解釈できることを示す．その上で，フェルミオンを定義する格子空間のトロポジーとその場合のダブラーの最大個数(トーラスであれば2^d)を結びつける新たな予想について言及し，その予想がグラフ理論の数学的問題に帰着されることを述べる． - Tatsuhiro MISUMITheoretical particle group seminar, Kyoto University 2022/07 Kyoto Kyoto University
We discuss the resurgence structure in asymptotically-free quantum field theory. We study the 2d O(N) sigma model at large N with a focus on an IR momentum cutoff scale A that regularizes IR singularities in the semiclassical expansion. Trans-series expressions for condensates are derived as series of the dynamical scale \Lambda (nonperturbative exponential) and coupling λ renormalized at the momentum scale μ. While there is no ambiguity when A > \Lambda, we find for A < \Lambda that the nonperturbative sectors have new imaginary ambiguities besides the well-known renormalon ambiguity in the perturbative sector. These ambiguities arise as a result of an analytic continuation of trans-series coefficients to a small value of the IR cutoff below the dynamical scale. We find that the imaginary ambiguities are cancelled each other when we take all of them into account. In particular, we show that the renormalon imaginary ambiguity is cancelled by the combined imaginary ambiguities at the orders \Lambda^4 and \Lambda^8 in the trans-series. We also find that some ambiguities vanish in A \to 0 limit and hence the resurgence structure changes when going from the semiclassical expansion to the exact result with no IR cutoff. We discuss the application of our analysis to other theories. - Tatsuhiro MISUMIRIMS online workshop "Exact WKB Analysis, Microlocal Analysis, Painlevé Equations and Related Topic" 2021/10
- S1 compactification and 't Hooft anomaly [Invited]Tatsuhiro MISUMIYITP domestic molecule-type workshop 2021/08
- Applications of Resurgence Theory to Quantum Theories: ZN-twist, Exact–WKB and Phase Transition [Invited]Tatsuhiro MISUMIApplicable resurgent asymptotics: Summary meeting 2021/06 Cambridge Cambridge University, Newton Institute
- Tatsuhiro MISUMICore-U seminai at Hiroshima University 2021/05 Hiroshima Hiroshima University
- リサージェンス理論に基づく非摂動効果の理解 [Invited]三角樹弘島根大学素粒子論グループセミナー 2021/03
- Tatsuhiro MisumiStrings & Fields 2020 2020/11
- Opening remarks & Brief introduction to resurgence [Not invited]Tatsuhiro MisumiYITP-RIKEN iTHEMS Molecule-type Workshop 2020 Potential Toolkit to Attack Nonperturbative Aspects of QFT -Resurgence and related topics- 2020/09
- 格子QCDへの応用に向けたCentral-branch Wilson fermionの研究 [Not invited]三角樹弘; 湯本純日本物理学会 2020秋季大会 2020/09
- ZNツイスト境界条件CPN-1模型における擬エントロピーの格子数値計算 [Not invited]三角樹弘; 藤森俊明; 伊藤悦子; 新田宗土; 坂井典佑日本物理学会 2020秋季大会 2020/09
- Tatsuhiro MisumiResurgence @ KITP 2020 2020/07 Santa Barbara, CA, US (online) US Santa Barbara, KITP
Quantum field theories on the circle-compactified spacetime are quite worth investigating in terms of finite-T physics, resurgence theory and volume independence. In particular, several evidences indicate that the compactified theories with ZN-twisted boundary condition maintain the vacuum structure of the original uncompactified theory. We discuss this property, called adiabatic continuity, and its implication on resurgence theory by looking into a couple of theories including CP^{N-1} model, Schwinger model, flag sigma model, and 4d QCD. The weapons we use in this talk include semiclassical analysis associated with complex solutions, 't Hooft anomaly matching, and lattice simulations. - Symmetries and Anomaly matching for central-branch Wilson fermion [Not invited]Tatsuhiro Misumi; Yuya TanizakiJPS 2020 meeting 2020/03 JPS
- Tatsuhiro MisumiCPN model workshop: recent developments and future 2020/01 Yokohama Keio University
- MISUMI TatsuhiroKEK Theory Group Seminar 2020/01 Tsukuba KEK
- Resurgent structure in quantum theories [Invited]MISUMI Tatsuhiro21th Singularity conference 2019/12
- Tatsuhiro MisumiKEK Theory workshop 2019 2019/12 Tsukuba KEK
- MISUMI TatsuhiroKyoto university, Yukawa institute particle group seminar 2019/11 YITP, Kyoto University YITP, Kyoto University
- Symmetry-protected topological phase and the related physics [Invited]MISUMI Tatsuhiro24th Niiyama Gasshuku 2019/10
- MISUMI TatsuhiroJPS autumn meeting 2019 2019/09 山形大学 日本物理学会
- MISUMI TatsuhiroJPS autumn meeting 2019 2019/09 山形大学 日本物理学会
- Lattice simulations of the twisted CP^{N-1} model [Not invited]MISUMI TatsuhiroJPS autumn meeting 2019 2019/09 山形大学 日本物理学会
- MISUMI TatsuhiroConference on discrete techniques on dynamics of fields and spacetime 2019 2019/09 Shimane University Shimane University
- MISUMI TatsuhiroTheoretical Particle Group Seminar at Chuo University 2019/08 中央大学 中央大学
- Lattice study on the twisted CP^{N-1} model on R x S^1 [Not invited]MISUMI TatsuhiroThe 37th international symposium on lattice field theory (Lattice2019) 2019/06 Wuhan China Lattice organizing committee
- MISUMI TatsuhiroNiigata University, Particle Theory Group seminar 2019/03
- MISUMI TatsuhiroHigher Symmetries: Theory and Applications 2019/03 Aspen Center for Physics Aspen Center for Physics (Caltech)
- Recent progress in 't Hooft anomaly matching [Invited]MISUMI Tatsuhiro23th Niiyama gasshuku meeting 2018/10
- MISUMI TatsuhiroJPS autumn meeting 2018 2018/09
- MISUMI TatsuhiroTheoretical Particle Group Seminar at Ibaraki University 2018/07 Mito city Theory group, Ibaraki University
- MISUMI TatsuhiroKEK Theory center seminar 2018/06 Tsukuba KEK
- MISUMI TatsuhiroThird informal workshop ”Variety and universality of bulk-edge correspondence in topological phases: From solid state physics to transdisciplinary concepts” 2018/05 Tsukuba Hatsugai Lab. Tsukuba University
- MISUMI TatsuhiroParticle Group Seminar at Nagoya University 2018/05
- MISUMI TatsuhiroParticle Group Seminar at Nagoya University 2018/05
- MISUMI TatsuhiroRIKEN STAMP seminar 2018/03
- Flat energy bands penetrating dispersive bands [Not invited]MISUMI TatsuhiroJPS meeting 2018 2018/03
- MISUMI TatsuhiroRIKKYO MathPhys 2018 2018/03
- MISUMI TatsuhiroTohoku University GP-PU seminar 2018/03
- MISUMI TatsuhiroITP group seminar at Kanazawa University 2017/11
- MISUMI TatsuhiroParticle Physics Group Seminar at Osaka University 2017/10
- MISUMI TatsuhiroThermal Field Theory and its Application 2017 2017/08
- MISUMI TatsuhiroProgress in Particle Physics 2017 2017/08
- MISUMI TatsuhiroParticle Physics Group Seminar at Nara Women's University 2017/06
- MISUMI TatsuhiroTopological Science Workshop 2017 Program 2017/02
- MISUMI TatsuhiroResurgence at Kavli IPMU 2016/12
- Quantum Non-Perturbative Analysis on Perturbation and Complex solutions [Not invited]MISUMI Tatsuhiro21st NIIgata-Yamagata Gasshuku 2016/11
- MISUMI TatsuhiroRIKEN iTHEMS-STAMP seminar 2016/11
- Non-BPS solutions and Bion configurations in CPN models [Not invited]MISUMI TatsuhiroJPS meeting 2016 autumn 2016/09
- Non-BPS Exact Solutions and their Relations to Bions [Not invited]MISUMI TatsuhiroResurgence in Gauge and String Theories 2016/07
- Resurgence and Topological Objects in Quantum Theories [Not invited]MISUMI TatsuhiroKeio University Topological Science Kick-off Symposium 2016/03
- Bions and Related Topics [Not invited]MISUMI TatsuhiroTopological Science Introductory Seminar 2015/11
- Finite-temperature phase transition in Z3-QCD [Not invited]MISUMI TatsuhiroJPS 2015/09
- Resurgence expansion in Sine-Gordon QM [Not invited]MISUMI TatsuhiroJPS 2015/09
- 複合ソリトン配位に基づく量子非摂動現象とResurgence展開 [Invited]MISUMI Tatsuhiro瀬戸内 Summer Institute 2015/09
- MISUMI Tatsuhiro33th International Symposium on Lattice Field Theory (Lattice2015) 2015/07
- Bion配位による量子非摂動現象とResurgence展開 [Invited]三角 樹弘山形大学理学部素粒子論グループセミナー 2015/07
- Bions and related physics [Invited]MISUMI Tatsuhiro理化学研究所初田研究室セミナー 2015/04
- Bions, Confinement and Resurgence [Invited]MISUMI Tatsuhiro慶應義塾大学理工学部セミナー 2015/04
- MISUMI TatsuhiroTopological solitons 2015 2015/02
- Bions, Confinement and Resurgence [Invited]MISUMI TatsuhiroKEK Theory Workshop 2015 2015/01
- MISUMI Tatsuhiro筑波大学素粒子論グループセミナー 2015/01
- MISUMI Tatsuhiro東京大学駒場素粒子論グループセミナー 2014/11
- Neutral bions are identical to IR-renormalons? ~Examples in CP^N-1 and Grassmann sigma models~ [Invited]MISUMI Tatsuhiro岡山光量子科学研究所セミナー 2014/11
- MISUMI Tatsuhiro東京工業大学素粒子論グループセミナー 2014/10
- Neutral bions in the CP^N-1 model [Not invited]MISUMI TatsuhiroJPS 2014 2014/09
- MISUMI Tatsuhiro離散的手法による場と時空のダイナミクス, 慶應義塾大学 2014/09
- Old lattice guy and Youngsters at BNL [Invited]MISUMI TatsuhiroHET-RBRC Symposium CreutzFest2014, Brookhaven National Lab. 2014/09
- Exact results in supersymmetric lattice gauge theories [Not invited]MISUMI TatsuhiroStrings and Fields 2014 2014/07
- MISUMI Tatsuhiro大阪大学素粒子論グループセミナー 2014/06
- Finite-temperstue phase transition in Z3-QCD [Not invited]MISUMI TatsuhiroJPS 2014 2014/03
- MISUMI Tatsuhiro筑波大学素粒子論グループセミナー 2014/03
- MISUMI Tatsuhiro計算基礎科学連携拠点 第2回JICFuSセミナー 2013/07
- QCD-like theories and HEP frontiers [Invited]MISUMI TatsuhiroKeio University particle theory group seminar 2013/05
- Hosotani mechanism redux [Invited]Tatsuhiro MISUMIRBRC Brain circulation Kick-off workshop 2013/03
- MISUMI TatsuhiroExtra Dimension 2013: Toward Extra-dimensions on the Lattice, 大阪大学 2013/03
- MISUMI TatsuhiroRIKEN-BNL Research Center Seminar, 2013/02
- MISUMI TatsuhiroBNL High Energy Theory Group Seminar 2012/09
- MISUMI Tatsuhiro30th International Symposium on Lattice Field Theory (Lattice2012) 2012/06
- New fermion discretizations and their application [Not invited]MISUMI TatsuhiroRBRC workshop "New Horizons for Lattice Computations with Chiral Fermions" 2012/05
- Flavored-mass terms for Naive and Staggered fermions [Not invited]Tatsuhiro MISUMIYIPQS-HPCI molecule workshop "New-type of Fermions on the Lattice" 2012/02
- Staggered-based Wilson and Overlap fermions [Not invited]MISUMI TatsuhiroHPCI国際研究会「計算的手法による素粒子論研究の広がり」 2011/12
- MISUMI Tatsuhiro新潟大学素粒子論研究室セミナー 2011/10
- Aoki phases in the staggered-Wilson fermions [Not invited]MISUMI Tatsuhiro29th International Symposium on Lattice Field Theory 2011/07
- Staggered versions of Wilson and Overlap fermions [Invited]MISUMI Tatsuhiro東京大学ハドロン理論研究室セミナー 2011/07
- Index theorem and Aoki phases in lattice fermions with flavored-mass terms [Invited]MISUMI Tatsuhiro高エネルギー加速器機構理論センター格子グループセミナー 2011/06
- Classification and Generalizations of Minimally Doubled Fermions [Invited]Tatsuhiro MISUMIKomaba Lattice mini-workshop 2011 2011/02
- Index Theorem and Overlap Formalism for Naïve and Minimally Doubled Fermions [Invited]MISUMI TatsuhiroBNL High Energy Theory Group Seminar 2010/10
- Toward Lattice QCD with Minimally Doubled Fermions [Not invited]MISUMI Tatsuhiro理研次世代格子ゲージシミュレーション研究会 2010/09
- MISUMI Tatsuhiro28th International Symposium on Lattice Field Theory 2010/06
- MISUMI Tatsuhiro日本物理学会 2010 年年次大会 2010/03
- MISUMI Tatsuhiro東京工業大学素粒子論研究室セミナー 2010/01
- MISUMI TatsuhiroAPCTP Junior Research Group Seminar 2009/12
- MISUMI Tatsuhiro大阪大学素粒子論研究室セミナー 2009/12
- MISUMI Tatsuhiro筑波大学素粒子理論研究室セミナー 2009/10
- AdS/QCD モデルに基づく有限温度メソンスぺクトルの研究 [Not invited]MISUMI Tatsuhiro日本物理学会 2009 年秋季大会 2009/09
- Quark Mass Dependence of Tc in AdS/QCD [Not invited]MISUMI TatsuhiroAPCTP Focus Program on Aspects of Holography and Gauge/String Correspondence 2009/07
- Tatsuhiro MISUMIString theory for Strongly Interacting System 2009 2009/06
- Finite-temperature spectral function of mesons in AdS/QCD [Invited]Tatsuhiro MISUMIQuarks and Hadrons under Extreme Conditions 2009 2009/05
- Electromagnetic response and pseudo-zero-mode Landau levels of bilayer graphene in a magnetic field [Not invited]MISUMI TatsuhiroTopological Aspects of Solid State Physics 2008 2008/06
- 二層グラフェンの磁場中電磁応答と実効ゲージ理論 [Not invited]MISUMI Tatsuhiro日本物理学会 2008 年年次大会 2008/03
MISC
- 木村太郎; 三角樹弘 素粒子論研究・電子版 30- (3) 2019/12
- Hongo Masaru; Fujimori Toshiaki; Misumi Tatsuhiro; Nitta Muneto; Sakai Norisuke Meeting Abstracts of the Physical Society of Japan 74.2- 2320 -2320 2019
- 藤森 俊明; 三角 樹弘; 坂井 典佑 日本物理学会誌 = Butsuri 73- (6) 352 -360 2018/06 [Refereed][Invited]
- Fujimori Toshiaki; Kamata Syo; Misumi Tatsuhiro; Nitta Muneto; Sakai Norisuke Meeting Abstracts of the Physical Society of Japan 73.1- 42 -42 2018
- 三角 樹弘 数理科学 54- (9) 56 -63 2016/09 [Invited]
- MISUMI Tatsuhiro 秋田大学大学院工学資源学研究科研究報告 (36) 15 -25 2015/10
- 三井 隆久; 寺沢 和洋; 三角 樹弘; 松浦 壮 慶應義塾大学日吉紀要. 自然科学 (56) 69 -79 2014/09
- Kouno Hiroaki; Kashiwa Kouji; Sakai Yuji; Misumi Tasuhiro; Sasaki Takahiro; Yahiro Masanobu Meeting abstracts of the Physical Society of Japan 68- (2) 29 -29 2013/08
- Misumi T; Nakano T Z; Kimura T; Ohnishi A Meeting abstracts of the Physical Society of Japan 67- (2) 36 -36 2012/08
- Nakano T; Misumi T; Kimura T; Ohnishi A Meeting abstracts of the Physical Society of Japan 67- (1) 14 -14 2012/03 [Refereed]
- 中野 嵩士; 三角 樹弘; 木村 太郎; 大西 明 素粒子論研究 119- (4) F161 -F166 2012/02
- Kimura Taro; Creutz Michael; Misumi Tatsuhiro Meeting abstracts of the Physical Society of Japan 66- (1) 8 -8 2011/03
- Misumi Tatsuhiro Meeting abstracts of the Physical Society of Japan 65- (1) 7 -7 2010/03
- Kimura Taro; Misumi Tatsuhiro Meeting abstracts of the Physical Society of Japan 65- (1) 7 -7 2010/03
- Misumi Tatsuhiro; Shizuya Ken-ichi Meeting abstracts of the Physical Society of Japan 63- (1) 681 -681 2008/02 [Refereed]
Awards & Honors
- 2015/03 Japan Particle and Nuclear Theory Forum Particle Physics Medal: Young Scientist Award in Theoretical Particle Physics
Adjoint QCD on R3 x S1 with twisted fermionic boundary conditions JPN japan_society受賞者: MISUMI Tatsuhiro
Research Grants & Projects
- 日本学術振興会：科学研究費助成事業 基盤研究(C)Date (from‐to) : 2023/04 -2027/03Author : 三角 樹弘
- Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Transformative Research Areas (A)Date (from‐to) : 2022/06 -2027/03Author : 福嶋 健二; 船井 正太郎; 塩崎 謙; 三角 樹弘
- JSPS：JSPS Grant-in-Aid CDate (from‐to) : 2019/04 -2023/03Author : MISUMI Tatsuhiro
- JSPS：Grant-in-Aid for Scientific Research BDate (from‐to) : 2018/04 -2022/03Author : SAKAI Norisuke
- JSPS：Grant-in-Aid for Young ScientistsDate (from‐to) : 2016/04 -2019/03Author : MISUMI Tatsuhiro
- RIMS, Kyoto University：RIMS WorkshopsDate (from‐to) : 2017 -2017Author : MISUMI Tatsuhiro
- JSPS：Grant-in-Aid for Young ScientistsDate (from‐to) : 2014/04 -2016/03Author : MISUMI Tatsuhiro
- KEK：Large-scale Simulation ResearchDate (from‐to) : 2013 -2016Author : MISUMI Tatsuhiro
- JSPS：Postdoctoral Fellowship for Research AbroadDate (from‐to) : 2012/04 -2013/05Author : Tatsuhiro MISUMI
- JSPS：Research Fellowship for Young ScientistsDate (from‐to) : 2009/04 -2012/03Author : MISUMI Tatsuhiro
- JSPS：Excellent Young Researcher Overseas Visit ProgramDate (from‐to) : 2010/04 -2011/03Author : MISUMI Tatsuhiro
Teaching Experience
- Mathematics for Physics IIMathematics for Physics II Kindai University
- Modern Physics IVModern Physics IV Kindai University
- Seminar on PhysicsSeminar on Physics Kindai University
- Physical ExperimentsPhysical Experiments Kindai University
- Basic seminar 2Basic seminar 2 Kindai University
- Quantum Field TheoryQuantum Field Theory Graduate School, Kindai University
- Drills for PhysicsIDrills for PhysicsI Kindai University
- Math for Physics IMath for Physics I Kindai University
- Computational Physics IComputational Physics I Kindai University
- Differential EquationsDifferential Equations Akita University
- Basic Analysis I, IIBasic Analysis I, II Akita University
- Quantum theory of many-particle systemsQuantum theory of many-particle systems Akita University
- Quantum informationQuantum information Akita University
- Analytical mechanicsAnalytical mechanics Akita University
- Special lecture on physics ASpecial lecture on physics A Hiroshima University
- Theoretical Physics SeminarTheoretical Physics Seminar Akita University
- Quantum mechanics (Exercise)Quantum mechanics (Exercise) Akita University
- Quantum and Mathematical PhysicsQuantum and Mathematical Physics Akita University
- Special lecture in PhysicsSpecial lecture in Physics Chuo University
- Fundamental physics II -Electromagnetics-Fundamental physics II -Electromagnetics- Akita University
- Natural Science (Physics)Natural Science (Physics) Keio University
- First-year seminarFirst-year seminar Akita University
- Experimental Mathematical ScienceExperimental Mathematical Science Akita University
- Special lecture A in physicsSpecial lecture A in physics Yamagata University, Faculty of Science
- Physics IPhysics I Keio University
- Physics IIPhysics II Keio University
- Physics 4Physics 4 Meiji Gakuin University
- Physics 3Physics 3 Meiji Gakuin University
Committee Membership
- 2022/04 - Today Japan Particle and Nuclear Theory Forum Committee member
- 2008/06 - Today Japan Particle and Nuclear Theory Forum Member
- 2007/12 - Today The Physical Society of Japan member
- 2020/04 -2022/03 National Center for University Entrance Examinations Member of Committee
- 2021/03 -2021/06 Cambridge University, Newton Institute Program organizer: Applicable resurgent asymptotics: towards a universal theory
- 2020/04 -2021/06 JSPS Screening committee of JSPS Fellow
- 2018/10 -2021/03 Akita High-Energy Accelerator Technology Forum Member
Social Contribution
- Handicraft class for children, Akita UniversityDate (from-to) : 2018/01-2018/01Role : DemonstratorCategory : Science cafeSponser, Organizer, Publisher : Akita UniversityEvent, Program, Title : Handicraft of wind-power mini-carHigh School-University connecting classesDate (from-to) : 2017/11/11-2017/11/11Role : LecturerCategory : Visiting lectureSponser, Organizer, Publisher : University Consortium AkitaEvent, Program, Title : Ohmagari High SchoolHandicraft class for children, Akita UniversityDate (from-to) : 2017/07-2017/07Role : DemonstratorCategory : Science cafeSponser, Organizer, Publisher : Akita UniversityEvent, Program, Title : Stable bridges composed of spaghettiHandicraft class for children, Akita UniversityDate (from-to) : 2016/10-2016/10Role : DemonstratorCategory : Science cafeSponser, Organizer, Publisher : Akita UniversityEvent, Program, Title : Handicraft of regular icosahedronDetecting natural radiationDate (from-to) : 2013/11/09-2013/11/10Role : LecturerCategory : Science cafeSponser, Organizer, Publisher : JST MiraikanEvent, Program, Title : Science Agora 2013