NEWS

Workshop Organization

This four-day "Shanghai-APCTP-Sogang workshop on Gravity, Astroparticle, and Cosmology (SASGAC 2025)" is the first research activity, primarily conducted among the Theory Center at Shanghai University, the Center for Quantum SpaceTime (CQUeST) at Sogang University, and the Asis Pacific Center for Theoretical Physics (APCTP). The main topics will include gravity theories, holography, Astroparticle Physics, Gravitational Waves, and Cosmology. It is planned to initiate and enhance the international collaboration, mainly but not restricted to three institutes, in a relaxed atmosphere with maximum discussion time, by providing participants with in-depth knowledge, practical skills, and collaborative discussions. The program will focus on interactions and discussions to maximise the opportunities for collaboration.

New Preprint

We apply physics-informed machine learning (PIML) to solve inverse problems in holography and classical mechanics, focusing on neural ordinary differential equations (Neural ODEs) and physics-informed neural networks (PINNs) for solving non-linear differential equations of motion. This manuscript aim to provide a systematic framework for using neural networks in inverse problems, serving as a comprehensive reference for researchers in machine learning for high-energy physics, with methodologies that also have broader applications in mathematics, engineering, and the natural sciences.

Workshop Organization

This Korea-Chile exchange APCTP workshop, hosted at the Asia Pacific Center for Theoretical Physics in Pohang, will bring together leading researchers to discuss recent advances in theoretical physics, covering high-energy physics, gravity, quantum field theory, and many-body physics. The event will cover a range of topics such as quantum information, black holes, condensed matter systems, and holographic dualities (AdS/CFT), as well as highlighting the intersection of these diverse areas. With distinguished speakers and opportunities for international collaborations, the workshop aims to deepen our understanding of gravity, matter, and the fundamental principles that govern the universe, offering novel insights into profound questions in modern physics.

Openings! Join us!!

The Junior Research Group (JRG), "Quantum Information, Black Holes, and Holography", at the Asia Pacific Centre for Theoretical Physics (APCTP) in Pohang, Korea, invites applications for postdoctoral positions. The starting date of the appointment is September 1, 2026.

We seek candidates in theoretical high-energy physics who will work closely with the JRG leader, Prof. Hyun-Sik Jeong, as well as other postdoctoral researchers at APCTP. Experience in one or more of the following areas is especially desirable: holography (gauge/gravity duality), quantum information theory, and machine learning applications in physics.

Deadline on December 15, 2025  |  Inspire-HEP  |  AcademicJobsOnline  |  APCTP

New Preprint

Building on the duality between Krylov complexity (KC) and geodesic length in Jackiw-Teitelboim, we develop a precise holographic dictionary for quantities in the Krylov subspace of the double-scaled Sachdev-Ye-Kitaev model (DSSYK). We elevate Krylov-space observables to sharp probes of bulk dynamics and topology in ensemble-averaged 2D gravity: (I) the growth rate of KC corresponds to the wormhole velocity, and its expectation value in coherent states serves as a boundary diagnostic of firewall-like structures via bulk reconstruction; (II) higher-order Krylov complexities capture connected bulk contributions encoded by replica wormholes; (III) Krylov entropy equals the von Neumann entropy of the parent-geometry density matrix obtained after tracing out baby universes.

New Member!

Dr. Ashutosh Tripathi joined our group 🎉🎉🎉. He got his Ph.D in Physics from High Energy Accelerator Research Organization (KEK), Japan. He is broadly interested in non-perturbative approaches to quantum field theory, lattice gauge theory, and matrix models motivated by string theory and quantum gravity. Recently, he has been investigating machine learning methods to encode physical symmetries and topological structures, aiming to achieve scalable simulations of strongly coupled systems. His long-term goal is to develop robust computational frameworks bridging fundamental theoretical physics and modern artificial intelligence to address open problems in high-energy and quantum many-body physics.

New Preprint

We study the quantum chaotic behavior of black holes within the brickwall model, focusing on probe scalar fields in hyperbolic AdS black holes. The brickwall model has captured the normal modes of AdS black holes with Gaussian-distributed boundary conditions on the stretched horizon and their connection to quantum chaos signatures of random matrix theory. Our results are supported by conventional diagnostics, including level spacing distributions and spectral form factors, as well as modern tools like Krylov complexity. We discuss the limitations of the brickwall model in capturing chaotic behavior in the parametrically large dimension limit, while emphasizing its effectiveness as a tool for studying quantum aspects of black holes in moderate higher dimensions.

New JRG Team on High-Energy Physics!

Starting September 2025, the new JRG team, "Quantum Information, Black Holes, and Holography", is established at APCTP. Our research areas include 

• Holography (gauge/gravity duality)

• Quantum information theory

• Machine learning applications in physics

Principal Investigator:  Hyun-Sik Jeong