Shanghai-APCTP-Sogang-GIST workshop on Gravity, Astroparticle, and Cosmology (SASGAC 2025)

Session

Morning II

Dec 28, 2025, 4:30 PM

Sogang University

Conveners

Morning II

• There are no conveners in this block

Morning II

• Lu Yin ()

Morning II

• There are no conveners in this block

Morning II

• There are no conveners in this block

Morning II

• Jeong-Hyuck Park ()

Morning II

• There are no conveners in this block

Morning II

• Stefano Scopel ()

Contribution list Timetable

16. Comments on dynamical gauge fields in holography

Dr Shuta Ishigaki

12/28/25, 4:30 PM

In holography, or the gauge/gravity correspondence, a local symmetry in the bulk usually translates into a global symmetry on the boundary. In order to introduce dynamical gauge fields in boundary field theory, the method of double-trace deformations has been utilized in various studies. However, this approach may always involve problems of unitarity violation. In this talk, we will review...

2. Schwarzian soft modes, Quantum Tsallis statistics and strange metal

Prof. Xian-Hui Ge

12/29/25, 9:30 AM

We develop a unified framework connecting quantum Tsallis statistics to electronic transport in strongly interacting systems. Starting from Rényi and Tsallis entropies, we construct a quantum Tsallis distribution that reduces to the conventional Fermi--Dirac distribution when q=1. For q slightly deviating from unity, the correction term in the occupation function can be mapped to a q-deformed...

19. Next Einstein Equations: Doubled Spacetime

Prof. Jeong-Hyuck Park

12/29/25, 10:30 AM

Double Field Theory (DFT) has emerged as a comprehensive framework for gravity, presenting a testable and robust alternative to General Relativity (GR), rooted in the ) symmetry principle of string theory. These lecture notes aim to provide an accessible introduction to DFT, structured in a manner similar to traditional GR courses. Key topics include doubled-yet-gauged coordinates,...

18. Reconstructing the dual gravity from entanglement entropy

Prof. Chanyong Park

12/29/25, 11:30 AM

In this work, we study how to reconstruct the dual gravity theory from the QFT data, especially entanglement entropy, by applying the rule-based method (holography).

We first attempt to derive a 3-dimensional black hole geometry from the entanglement entropy of a 2-dimensional thermal system composed of two distinct types of matter. Using the reconstructed black hole geometry, we determine...

21. Geometric realization of the concept of 'charge without charge'

Prof. Wonwoo Lee

12/29/25, 1:30 PM

22. Imprints of Chaos in Gravitational Waves in EMRIs with Dehnen-type Dark Matter Halos

Dr Surojit Dalui

12/29/25, 2:30 PM

We investigate the signature of chaos in gravitational waves from an extreme-mass-ratio inspiral configuration, where a stellar massive object, confined in a harmonic potential, orbits a supermassive Schwarzschild-like black hole embedded in a Dehnen-type dark matter halo. First, we demonstrated the system's transition from non-chaotic to chaotic dynamics by analysing Poincaré sections,...

25. Scalarization of quantum Oppenheimer-Snyder black holes

Prof. Yun Soo MYUNG

12/29/25, 3:20 PM

We obtain quantum parameter-mass induced spontaneous scalarization of quantum Oppenheimer-Snyder (qOS)-black hole in the Einstein-Gauss-Bonnet-scalar (EGBS) theory with the unknown qOS action. It is turned out that two Davies points of heat capacity are identified with two critical onset mass and quantum parameter, showing a strong connection between thermodynamics of bald black hole and...

24. Neural Network-Based Methods for Inverse Problems in Holography

Prof. Hyun-Sik Jeong

12/29/25, 4:20 PM

Holography (AdS/CFT) provides a powerful framework for studying the quantum nature of gravity and strongly coupled quantum systems. This talk showcases how deep neural networks can address inverse problems in holography: specifically, reconstructing bulk gravity models from boundary observables. By integrating holography with physics-informed neural networks, we show that strongly coupled...