Conveners
Parallel Session: IA
- Hajime Aoki (Saga University)
Parallel Session: IB
- Sinya Aoki (Fundamental Quantum Science Program, RIKEN)
Parallel Session: IIA
- Satoshi Yamaguchi (The University of Osaka)
Parallel Session: IIB
- Nobuyoshi Ohta (NITEP, Osaka Metropolitan University)
Parallel Session: IIIA
- Ryo Yokokura (Keio U.)
Parallel Session: IIIB
- Yoshifumi Hyakutake (Ibaraki Univ.)
Parallel Session: IVB
- Kohtaroh Miura (University of Tsukuba)
Parallel Session: IVA
- Matsuo Sato (Hirosaki University)
Description
A (left): K03 Seminar Hall. B (right): K03 Meeting Room I.
| Row | Date and time (JST) | A (left) | B (right) |
|---|---|---|---|
| I | 25 Nov, 14:50โ16:30 | IA | IB |
| II | 25 Nov, 16:50โ18:10 | IIA | IIB |
| III | 26 Nov, 14:50โ16:30 | IIIA | IIIB |
| IV | 26 Nov, 16:50โ18:10 | IVA | IVB |
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Harold Steinacker (University of Vienna)25/11/2026, 14:50
We describe how an expanding and asymptotically flat 3+1 dimensional homogeneous and isotropic spacetime arises from the IKKT matrix model at one loop, within a weak coupling regime. Some aspects of the emergent gravity theory are also discussed, which deviates form general relativity in the extreme UV and IR regimes.
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Nagare Katayama (YITP, Kyoto University)25/11/2026, 14:50
Understanding the microscopic origin of confinement and the other gapped phases in four-dimensional YangโMills theory remains a central challenge. The Wilsonโโt Hooft classification constrains these phases through the behavior of electric and magnetic line operators. The CardyโRabinovici model provides an abelian setting in which to study confinement, oblique confinement, and duality. In our...
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Henry Liao (National Tsing Hua University)25/11/2026, 15:10
In the Lorentzian IKKT theory, space and time are not assumed in a priori but are described by the dynamics of matrices. Since classical saddles are expected to be the dominant contributions to path integral, it is crucial to solve the equations of motion for these matrices that describe spacetime. In this work, we apply Lie-algebraic ansatz to solve the Lorentzian IKKT matrix model. Through...
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Sho Araki (The University of Osaka)25/11/2026, 15:10
Symmetric mass generation (SMG) is a mechanism for opening a gap without spontaneous symmetry breaking, first demonstrated by Fidkowski and Kitaev in a one-dimensional Majorana-chain model. We formulate the model as a Euclidean path integral on a two-dimensional lattice, with and without domain walls. Our numerical results show that four-fermion interactions can gap out the Majorana mode...
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Soma Onoda (Kyushu University)25/11/2026, 15:30
Recently, lattice formulations of two-dimensional chiral gauge theories via bosonization have been developed. These formulations are based on bosonโfermion duality in the continuum limit. In this talk, we present a lattice construction of the gauged WessโZuminoโWitten (WZW) model for two-dimensional $SU(N)$ chiral gauge theories. The WZW model contains a three-dimensional bulk contribution...
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Asato Tsuchiya (Shizuoka University)25/11/2026, 15:30
Recently, the construction of three-dimensional conformal field theories (3D CFTs) using interacting fermions in the lowest Landau level on a sphere has attracted considerable attention. Although this approach is known as fuzzy-sphere regularization, it differs from conventional field theories on the fuzzy sphere. In this talk, we investigate the universality of this construction by...
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Satoshi Yamaguchi (The University of Osaka)25/11/2026, 15:50
We investigate the photon phase of four-dimensional $\mathbb{Z}_4$ lattice gauge theory. The theory has a plaquette action with two coupling parameters and exhibits various phases depending on their values. Among them is the photon phase, whose low-energy effective theory is believed to be described by Maxwell theory. On the other hand, this lattice gauge theory possesses a duality, and an...
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Karin Yukuhiro (The University of Tokyo)25/11/2026, 15:50
Homotopy algebras provide a universal algebraic framework for constructing correlation functions in quantum field theory. Motivated by the study of openโclosed duality from the perspective of string field theory, we aim to incorporate the 1/N expansion into this framework. As a first step, we propose an algebraic formula for perturbative correlation functions in the large-N limit of a...
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Kohtaroh Miura (University of Tsukuba)25/11/2026, 16:10
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Tatsuya Endo (University of Tsukuba)25/11/2026, 16:10
String Field Theory (SFT) aims to provide a non-perturbative formulation of string theory, and various types of actions have been constructed within this framework. Understanding the transformations between these actions leads to the unification of different formulations, the clarification of correspondences, and the proof of their equivalence. In recent years, T.Erler and H.Matsunaga have...
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Siye Wu (National Tsing Hua University)25/11/2026, 16:50
Higher-form symmetries introduced in the work of Gaiotto-Kapustin-Seiberg-Willet are global symmetries whose action on the quantum Hilbert space depend on extended objects and so are the charged objects. In this talk, we explore the classical origin of higher-form symmetries as actions of certain cohomology groups on fields and some of its consequences.
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Yoshinori Matsuo (Kyoto University)25/11/2026, 16:50
In Einstein gravity, matter with an arbitrarily small density can be a black hole. Pressure in the star diverges if size of the star is smaller than 9/8 of the Schwarzschild radius, implying the gravitational collapse into a black hole. By taking quantum effects of matter, however, pressure is bounded from above, and a core with negative energy appears instead. Density of matter increases and...
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Ryo Yokokura (Keio U.)25/11/2026, 17:10
Axion models often face the domain wall problem, which threatens the standard big-bang cosmology. The Lazarides-Shafi mechanism attempts to resolve this by identifying degenerate vacua through a continuous gauge symmetry. We formulate a topological quantum field theory to isolate the essential structure of the mechanism and analyze its generalized symmetry structure, including higher-form...
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Yu Miyauchi (Keio University)25/11/2026, 17:10
We study the effects of massive KaluzaโKlein (KK) modes on the two-dimensional effective theory obtained from four-dimensional EinsteinโMaxwell theory. We show that the background electric field induces mixing between massive Maxwell KK modes and massless graviphotons, generating corrections to the graviphoton kinetic term at tree level and one loop. In particular, the tree-level correction...
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Shotaro Kawanago (SOKENDAI, KEK)25/11/2026, 17:30
We provide a comprehensive study of anomalies and discrete torsion in the worldsheet theories of Type II and Type I string theories on a general ten-dimensional target space. In the modern understanding, the anomaly of a worldsheet theory is characterized by an invertible field theory in three dimensions, and invertible field theories are classified by the Anderson dual of a suitable ...
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Wei-Hsiang Shao (RIKEN iTHEMS)25/11/2026, 17:30
Scale dependence is a common feature of effective spacetime geometries that emerge from nonperturbative aspects of quantum gravity. In this talk, I will investigate how such scale dependence can substantially modify the conventional properties of Hawking radiation. I consider a framework in which the position and mass of the collapsing matter that forms a black hole depend on the momentum of...
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Takeshi Morita (Shizuoka University)25/11/2026, 17:50
In this talk, I introduce two properties of chaotic systems, such as double pendulums, in the semi-classical regime: 1) We can derive a simple effective Hamiltonian for fluctuations around the classical chaotic trajectory. 2) By quantizing the fluctuations, the Hamiltonian reveals that they obey an emergent thermodynamics similar to the Hawking phenomenon observed in black holes. These two...
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Hiroki WADA (Tohoku University)25/11/2026, 17:50
The tertiary invariant is a recently introduced pairing between two-dimensional minimally supersymmetric field theories, motivated by topological modular forms. We evaluate this invariant directly from its definition for the sigma model on Sp(2) with unit H-flux paired with the internal theory of the ten-dimensional non-supersymmetric tachyon-free heterotic string, as well as for the sigma...
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Ken Kikuchi (International Centre for Theoretical Sciences)26/11/2026, 14:50
We present a compact formula for the exact partition function of the $d$-dimensional arithmetic Ising model (AIM). For a $2\times2$ system, we express it analytically using the $q$-Hurwitz-Lerch zeta function and derive explicit forms for the free energy and entropy. Additionally, we find that the entropy increases at high temperatures, supporting the presence of entropic order.
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Hiroki Hoshina (Independent Researcher)26/11/2026, 14:50
We numerically study the non-perturbative renormalization group flow of general quadratic gravity, using the flow equations derived by Sen, Wetterich and Yamada, with boundary conditions consistent with the Hubble scale, laboratory tests of gravity and Starobinsky inflation. By a slight shift of the infrared reference scale, we obtain trajectories that avoid the infrared singular behavior near...
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Nobuyoshi Ohta (NITEP, Osaka Metropolitan University)26/11/2026, 15:10
We study the quantum aspects of the conformal gravity in four dimensions, specifically addressing a known discrepancy in beta functions between general quadratic curvature theories and conformal gravity, which corresponds to two scalar degrees of freedom. We demonstrate that this mismatch is resolved by carefully introducing gauge-fixing and ghost terms via the BRST symmetry, which effectively...
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Haruki Nakayama (The University of Osaka)26/11/2026, 15:10
Defects, such as impurities, boundaries, and interfaces, are ubiquitous in physical systems and provide useful probes of the dynamics of quantum field theories. In particular, conformal defects play an important role in understanding the universal properties of critical phenomena in such systems. While most previous studies have focused on defects preserving rotational symmetry in the...
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Jun Maeda (Kyoto University)26/11/2026, 15:30
We develop an analytic endpoint bootstrap for conformal Wilson lines in critical bosonic QED$_3$ with $N$ complex scalar flavors. The endpoints of a Wilson line can be regarded as defect-changing operators between the trivial defect and the Wilson line, and their four-point functions relate the bulk and Wilson-line spectra. We compute the normalized endpoint four-point correlator through...
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Maki Takeuchi (Kobe University)26/11/2026, 15:30
We investigate the vacuum structure of a complex scalar field on a two-dimensional torus with quantized magnetic flux M. A characteristic feature of this system is that a nonvanishing vacuum expectation value with nontrivial dependence on the coordinates of the torus emerges when the torus area exceeds a critical value. Using the lowest-mode approximation, we find one, two, and six vacuum...
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Matsuo Sato (Hirosaki University)26/11/2026, 15:50
To identify the vacuum corresponding to our universe among the vast number of vacuum candidates in string theory, we focus on searching for minima of the potential within a non-perturbative formulation. To efficiently generate string backgrounds determined by the geometry of internal spaces, we formulate the correspondence between simplicial complexes and colored graphs in terms of matrix...
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Alvaro Pastor Gutierrez (RIKEN iTHEMS)26/11/2026, 15:50
Dynamical symmetry breaking plays a crucial role in mass and scale generation. In QCD-like theories, its dependence on the number of fermion flavours determines the phase structure and the transition to the conformal regime. In this work, we compute non-perturbative corrections relevant to this phenomenom, including momentum dependencies and field invariants essential for an adequate...
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Kazuya Murakami (Keio University)26/11/2026, 16:10
The Higgs mechanism in gauge theories can give rise to topological solitons. Nontrivial homotopy groups of the vacuum manifold can support different types of topological solitons. In this talk, we focus on vortices associated with the first homotopy group. Unlike higher homotopy groups, the first homotopy group can be non-Abelian. This non-Abelian structure may give rise to vortex phenomena...
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Shirabe Endo (KEK/SOKENDAI)26/11/2026, 16:10
Superstring theory can produce an enormous number of four-dimensional vacua of order 10^100, and most of these vacua have a negative cosmological constant. Since our universe has a small positive cosmological constant, we need to find such vacua. Computational methods are good approaches to this problem, but the necessary computational cost becomes a large issue. In this work, we...
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Sinya Aoki (Fundamental Quantum Science Program, RIKEN)26/11/2026, 16:50
We propose to use the AdS/CFT correspondence as a regularization of CFT operators. We first derive basic properties of bulk-boundary 2-pt functions as distributions (hyper-functions), and apply them to the GKP-Witten relations to show how it is regularized. We then extend our discussion to 3-pt functions and derive the Ward-Takahashi identities of the EMT (energy momentum tensor) including the...
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Hayate Kimura (SOKENDAI)26/11/2026, 16:50
Quantum reference frames (QRFs) provide a relational description of time and observables in quantum gravity. Unlike asymptotically AdS spacetimes, de Sitter (dS) spacetime lacks a natural temporal reference system associated with an asymptotic spatial boundary. Chandrasekaran, Longo, Penington, and Witten (CLPW) address this by explicitly introducing physical observer degrees of freedom as an...
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Leon Miyahara (Nagoya university)26/11/2026, 17:10
In $AdS_3/CFT_2$, the gravity sector includes not only supergravitons but also states involving singletons. In our previous work, we studied the construction of this gravity sector in the D1-D5 CFT at $N=2$. In this talk, we extend the analysis to general $N$. We also investigate the lifting of BPS states under deformations away from the free orbifold point. This talk is based on ongoing work...
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Kei-Ichi Kondo (Chiba University)26/11/2026, 17:10
We present a formulation for understanding color confinement on the basis of quantum reference frames (QRFs) and relational observables. In the QRF approach to color confinement, colored quantities are not defined as isolated local fields, but rather as relational observables with respect to a color frame or a dressing field. By the Gauss law, local color charge is excluded from the physical...
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Kensei Tanaka (Chuo university)26/11/2026, 17:30
In relativistic chiral matter, the generation and dissipation of axial charge compete with each other. Although the axial charge relaxation time is a key quantity characterizing such systems, it is usually treated as a phenomenological constant, and perturbative methods are not applicable at strong coupling. In this study, we investigate the axial charge relaxation time in a strongly coupled...
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Junya Yamagishi (Chiba University)26/11/2026, 17:30
The idea that physical constants and symmetries can be determined by extremizing the entanglement generated in scattering has attracted considerable attention in recent years. In gluon $2\to2$ scattering, however, extremizing bipartite entanglement alone does not uniquely recover gauge invariance, and an additional criterion based on the nonstabilizerness of quantum states is required. Here...
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Jun Nishimura (KEK, SOKENDAI)26/11/2026, 17:50
We have recently succeeded in developing a new method that allows us to calculate quantum real-time evolution of a system, which is coupled to a von-Neumann measurement device and a huge environment. Using such explicit calculations, we explore the measurement problem based on new ideas including post-selections and the weak value.
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Yoshifumi Hyakutake (Ibaraki Univ.)26/11/2026, 17:50
It is well known that perturbative corrections to type II supergravity or 11 dimensional supergravity start from (Riemann)^4 terms. Since D6-branes are uplifted to KK-monopoles in the M-theory, which are purely geometrical objects, it is possible to investigate corrections to such objects beyond supergravity. In this talk, we construct near horizon limit of D6-branes/KK-monopoles under the...
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