KEK Theory Workshop 2025

16 Dec 2025, 09:00 → 18 Dec 2025, 18:00 Asia/Tokyo

K03 Seminar Hall (KEK Tsukuba Campus)

KEK Theory Workshop is an annual workshop on string theory and quantum field theory. Since KEK Theory Workshop 2014, it has been held as an international workshop. Speakers are invited from abroad as well as from Japan, and all talks are given in English.

This year we aim to provide a valuable opportunity to have extensive discussions on new developments in string theory, the gauge-gravity duality, real-time evolution of quantum systems, bootstrap approach, lattice construction of chiral gauge theories, non-equilibrium statistical mechanics and open quantum systems. The invited speakers are selected from various research fields, and we have asked them to give a pedagogical exposition of the big picture in their own research field with the right amount of technical details, which are useful in building up a comprehensive understanding of the notions and their mutual relationship.

The workshop will be ON-SITE at KEK Tsukuba Campus on December 16 (Tue.) -- 18 (Thu.), 2025, without on-line attendance. Please visit K03 Building.

Invited Speakers

• Dec.16 (Tue)
  - Tetsuya Onogi (The University of Osaka)
      Anomalies and the domain-wall fermion
  - Yuya Kusuki (Kyushu University)
      Bootstrapping Boundary Conformal Field Theory
  - Kazumi Okuyama (Shinshu University)
       Recent developments in double-scaled SYK
• Dec.17 (Wed)
  - Masatoshi Sato (Kyoto University)
      Hermitian topological boundary states as open quantum systems
  - Takahiro Sagawa (The University of Tokyo)
      Topology of nonlinear dynamics
  - Yasuaki Hikida (Osaka Institute of Technology)
      Complex saddles of de Sitter gravity via holography
• Dec.18 (Thu)
  - Kazuya Yonekura (Tohoku University)
      Heterotic string theory and N=(0,1) supersymmetric field theory
  - Kanato Goto (The University of Osaka)
      Fake Structures in dS Holography and Black Hole Interiors

Short Talks

We will arrange short talk sessions on more diverse topics, for which participants can apply. If there are too many applicants, we will have to make some selection.

Workshop Registration

• Registration Deadline: Oct. 31 (Fri), 2025.
• Please indicate your requests for: financial support, VISA, banquet participation, and a short talk presentation.
• No registration fee.
• The banquet will be held in the evening on the first day (Dec. 16th) at KEK in the lounge in front of the Kobayashi Hall. The fee will be 3000Yen for students, 5000Yen for faculty staffs / postdocs.

Notice

• Accommodation: KEK dormitory slots are limited.  For Urban hotel, a discount reservation is avairable. See details here.
• We will ask 500 Yen for coffee/snacks.

Scam Email Warning

Please be aware of potential scams claiming to make housing reservations on your behalf. We were made aware of some participants receiving such messages from "Conferences@reservationsmanagement.org" or similar addresses. Please ignore such emails and do not reply, do not click shared links, and do not provide your credit card information.

Organizers

Yuta Hamada, Gregory Joseph Loges, Kohtaroh Miura,
Shun'ya Mizoguchi, Jun Nishimura, Hiroki Ohata

Secretary

Yuko Ohno (Ms.)  yukoohno[at]post.kek.jp
(Please replace [at] with @.)

Tuesday, 16 December

09:00 → 09:20 Reception

09:20 → 09:30 Opening Address

09:20 Welcome to KEK Theory Workshop 2025

Speaker: Dr Kohtaroh Miura (KEK)

09:30 → 10:30 Plenary Session: I

Convener: Prof. Takeshi Morita (Shizuoka University)

09:30 APS index and the domain-wall fermion

Speaker: Prof. Tetsuya Onogi (Osaka University)

10:30 → 10:45 Coffee Break

10:45 → 11:45 Plenary Session: II

Convener: Prof. Takeshi Morita (Shizuoka University)

10:45 Bootstrapping Boundary Conformal Field Theory

Speaker: Prof. Yuya Kusuki (Kyushu University)

11:45 → 13:30 Lunch Break

13:30 → 14:30 Plenary Session: III

Convener: Prof. Takeshi Morita (Shizuoka University)

13:30 Recent developments in double-scaled SYK

Speaker: Prof. Kazumi Okuyama (Shinshu University)

14:30 → 14:50 Coffee Break

14:50 → 16:30 Parallel Session: IA

Convener: Prof. Asato Tsuchiya (Shizuoka University)

14:50 Towards a Hamiltonian Framework for String-Inspired Nonlocality

Speaker: Dr Wei-Hsiang Shao (RIKEN iTHEMS)

15:10 Anomaly-induced negative magnetoresistance in D3-D7 systems in holography

Speaker: Prof. Shin Nakamura (Chuo University)

15:30 Fundamental structure of string geometry theory

Speaker: Prof. Matsuo Sato (Hirosaki University)

15:50 TBD

Speaker: Dr Gregory Loges (KEK)

16:10 Twist field deformations in string field theory

Speaker: Mr Xianghang Zhang (Nagoya University)

14:50 → 16:30 Parallel Session: IB

Convener: Prof. Sinya Aoki (RIKEN)

14:50 Chiral Anomaly in $(3+1)$-dimensional Staggered Fermion System

Speaker: Dr Shoto Aoki (RIKEN iTHEMS)

15:10 How to formulate the Z_8 topological invariant of Majorana fermion on a lattice

Speaker: Mr Sho Araki (Osaka University)

15:30 Non-singlet conserved charges and anomalies in 3+1 D staggered fermions

Speaker: Mr Tatsuya Yamaoka (Osaka University)

15:50 Simulating the real-time quantum evolution by the Lefschetz thimble method

Speaker: Prof. Jun Nishimura (KEK/SOKENDAI)

16:10 TBD

Speaker: Mr Naoyuki Yamamori (KEK/SOKENDAI)

16:30 → 16:50 Coffee Break

16:50 → 17:50 Parallel Session: IIA

Convener: Dr Wei-Hsiang Shao (RIKEN iTHEMS)

16:50 Unified exact WKB framework for quantum resonance and scattering theory

Speaker: Dr Okuto Morikawa (RIKEN iTHEMS)

17:10 TBD

Speaker: Mr Tin-Long Chau (KEK/SOKENDAI)

17:30 TBD

Speaker: Mr Cheng-Tsung Wang (KEK/SOKENDAI)

16:50 → 18:10 Parallel Session: IIB

Convener: Dr Tadakatsu Sakai (KMI / KEK)

16:50 High-Energy Pion Scattering in Holographic QCD

Speaker: Mr Bartosz Pyszkowski (Kyoto University, YITP)

17:10 Large θ angle in the two-dimensional large N CP^{N-1} model

Speaker: Mr Tsubasa Sugeno (Tohoku University)

17:30 Bootstraping quantum mechanics

Speaker: Prof. Takeshi Morita (Shizuoka University)

17:50 Causal Bounds on EFTs with anomalies with a Pseudoscalar, Photons, and Gravitons (bootstraping EFT)

Speaker: Dr Jaehoon Jeong (KIAS)

18:30 → 20:15 Banquet

Wednesday, 17 December

09:30 → 10:30 Plenary Session: I

Convener: Prof. Shin Nakamura (Chuo University)

09:30 Hermitian topological boundary states as open quantum systems

Speaker: Prof. Masatoshi Sato (Kyoto University)

10:30 → 10:45 Coffee Break

10:45 → 11:45 Plenary Session: II

Convener: Prof. Shin Nakamura (Chuo University)

10:45 Topology of nonlinear dynamics

Speaker: Prof. Takahiro Sagawa (The University of Tokyo)

11:45 → 12:00 Group Photo: (in front of K03 Building)

12:00 → 13:30 Lunch Break

13:30 → 14:30 Plenary Session: III

Convener: Prof. Shin Nakamura (Chuo University)

13:30 Complex saddles of de Sitter gravity via holography

Speaker: Prof. Yasuaki Hikida (Osaka Institute of Technology)

14:30 → 14:50 Coffee Break

14:50 → 16:30 Parallel Session: IA

Convener: Prof. Matsuo Sato (Hirosaki University)

14:50 No-boundary Proposal and Hořava-Lifshitz Gravity

Speaker: Dr Hiroki Matsui (Nihon University)

15:10 Kaluza–Klein photon contribution to charged black hole in 2D perspective

Speaker: Mr Yu Miyauchi (Keio University)

15:30 Effective Dynamics of Spherically Symmetric Static Spacetime

Speaker: Dr Yuki Yokokura (KEK)

15:50 Essential Renormalization Group Equation for Gravity coupled to a Scalar field

Speaker: Prof. Nobuyoshi Ohta (Osaka Metropolitan University)

16:10 On Nonlinear-Supersym metric General Relativity(NLSGR)

Speaker: Prof. Kazunari Shima (Saitama Institute of Technology)

14:50 → 16:30 Parallel Session: IB

Convener: Prof. Tetsuya Onogi (Osaka University)

14:50 Holography by conformal smearing

Speaker: Prof. Sinya Aoki (RIKEN iTHEMS)

15:10 Quark confinement due to symmetric instantons reflecting holography

Speaker: Prof. Kei-Ichi Kondo (Chiba University)

15:30 Dyonic lines in 3d monopole semiclassics

Speaker: Dr Yui Hayashi (Kyoto University, YITP)

15:50 Lefshetz thimble study of U(1) gauge theory in 1 + 1 dimensions

Speaker: Dr Hiroki Ohata (KEK)

16:10 Complex Langevin Lattice QCD at Extremely High Density for Color Superconductivity

Speaker: Dr Kohtaroh Miura (KEK)

16:30 → 16:50 Coffee Break

16:50 → 18:30 Parallel Session: IIA

Convener: Dr Yuki Yokokura (KEK)

16:50 Higher-form symmetries and spin structure in axion electrodynamics

Speaker: Dr Ryo Yokokura (Keio University)

17:10 Vacuum structures of QCD2 from non-invertible anyon condensation

Speaker: Dr Naoto Kan (Osaka University)

17:30 Modified entangled states for perfect quantum teleportation

Speaker: Mr Sora Kobayashi (Chiba University)

17:50 Semi-classical correspondence between Petz map and Bayes' rule: from Lindbladian to reverse diffusion

Speaker: Mr Ryota Nasu (Shizuoka University)

18:10 Description of curved spaces by finite-size matrices

Speaker: Mr Tatsuya Seko (Shizuoka University)

16:50 → 18:30 Parallel Session: IIB

Convener: Dr Gregory Loges (KEK)

16:50 The E11-Inspired Approach to Gravity

Speaker: Dr Keith Glennon (OIST)

17:10 Higher-derivative theory of fermion and supersymmetry

Speaker: Prof. Takeo Inami (RIKEN)

17:30 When Disorder Meets Conformal Defects: The Emergence of Logarithmic Structures

Speaker: Mr Soichiro Shimamori (Osaka University)

17:50 Algebraic Structure in the Exact Renormalization Group

Speaker: Mr Taichi Tanaka (Nihon University)

18:10 On anomalies in family unification models

Speaker: Dr Hiroki Wada (Tohoku University)

Thursday, 18 December

09:30 → 10:30 Plenary Session: I

Convener: Prof. Tamiaki Yoneya (The University of Tokyo)

09:30 Heterotic string theory and N=(0,1) supersymmetric field theory

Speaker: Prof. Kazuya Yonekura (Tohoku University)

10:30 → 10:45 Coffee Break

10:45 → 11:45 Plenary Session: II

Convener: Prof. Tamiaki Yoneya (The University of Tokyo)

10:45 Holography for a Closed Universe with a Quantum Reference Frame

Speaker: Prof. Kanato Goto (Osaka University)

11:45 → 12:00 Closing Address: Summary and Future Prospect

Convener: Prof. Jun Nishimura (KEK/SOKENDAI)