The conference proceeds in a hybrid mode with several remote speakers from overseas included and all talks broadcast. Domestic participants are asked to attend it on site and those overseas on line.  In addition, please be mindful that a zoom access is also granted to those domestic colleagues under teaching duties, involving actual classes this semster, with their partial off-line attendance understood. If you belong to the latter group and need an access, please alert LOC.

 

*The above dates and times are based on Korea Standard Time (KST) Time Zone (UTC/GMT + 9 hours)

 

• September 11 (Mon)

 

10:00-11:00 Hirosi Ooguri (CALTECH)

Title: Symmetry Resolution at High Energy

Abstract: The density of states of a unitary quantum field theory is known to have a universal behavior at high energy. In two dimensions, this behavior is described by the Cardy formula. When the theory has symmetry, it is interesting to find out how the Hilbert space is decomposed into irreducible representation of the symmetry. In this talk, I will derive universal formulas for the decomposition of states at high energy with respect to both internal global symmetry and spacetime symmetry. The formulae are applicable to any unitary quantum field theory in any spacetime dimensions. As a byproduct, we resolve one of the outstanding questions on the stability of non-abelian black holes. We will also derive the high energy asymptotic behavior of correlation functions.

 

11:15-12:15 Emil Martinec (EFI, University of Chicago)

Title: BTZ black holes from the worldsheet

Abstract: We discuss two aspects of worldsheet string dynamics in the presence of AdS3 (BTZ) black holes. First, we construct AdS3 orbifolds describing conical defect geometries that prepare pure state black holes through Euclidean evolution, and examine aspects of the bulk/boundary correspondence. Second, BTZ black holes can discharge by radiating wound strings; the emission probability contains lessons for the nature of Hawking radiation.

 

12:30-14:00 Lunch

 

14:00-15:00 Seung-Joo Lee (IBS)

Title: Non-minimal 7-Branes beyond Kodaira

Abstract: As part of a longer program for deciphering the nature of the boundaries of quantum gravity moduli spaces, we investigate the 7-branes described in F-theory by non-minimal elliptic fibers. Unlike the minimal Kodaira fibers describing a Lie-type gauge enhancement at finite distance, the non-minimal fibers can arise as infinite distance limits in the open string moduli space and lead to a rich variety of stable degenerations. In this talk, focusing on such limits, I will first review our earlier analysis of F-theory on K3 surfaces and will proceed to report on recent progress in the study of F-theory on Calabi-Yau threefolds. As one of the novelties in six dimensions, a class of these open string limits will be interpreted as triggering (dual) decompactifications with defects.

 

15:15-16:15 Jan Manschot (Trinity College Dublin)

Title: Topological correlators of massive N=2 SQCD and 5d N=1 YM

Abstract: I will discuss correlation functions of topologically twisted Yang-Mills theories on a compact four-manifold X. After a general introduction, I will explain correlation functions of 1) N=2 Yang-Mills theory with massive fundamental hypermultiplets, and 2) 5d N=1 Yang-Mills compactified on X times S^1. For gauge group SU(2), the correlation functions reduce in the low energy effective field theory to an integral over a fundamental domain in the upper-half plane. Correlation functions of the theories give rise to topological invariants of X, such as Segre numbers and K-theoretic invariants.

 

16:30-17:30 Hiraku Nakajima (Kavli IPMU)

Title: Coulomb branches of orthosymplectic quiver gauge theories

Abstract: We review a mathematical definition of Coulomb branches of 3d N=4 SUSY gauge theories, and a method to identify them with concrete spaces. Then we apply the method to identify Coulomb branches of orthosymplectic quiver gauge theories.

 

• September 12 (Tue)

 

10:00-11:00 Sameer Murthy (King's College London)

Title: New attractors for the black hole index 

Abstract: The count of black hole microstates is typically obtained from a supersymmetric index in weakly coupled string theory. I will discuss the index in the strongly coupled theory, as a functional integral in N=2 supergravity in asymptotically flat space. The saddle-points of this index are given by supersymmetric ​"finite-temperature" rotating geometries. I will discuss a new version of the attractor mechanism obeyed by these geometries: the scalar fields at the poles of the Euclidean horizon as well as the free energy of the black hole get attracted to values that depend only on the charges and are independent of the asymptotic moduli and temperature. 

 

11:15-12:15 Boris Pioline (CNRS)

Title: Counting BPS black hole micro-states with (mock) modular forms

Abstract: A central problem in quantum gravity is to get a quantitative microscopic interpretation of the Bekenstein-Hawking entropy of black holes. In type II strings compactified on a Calabi-Yau manifold, BPS black hole microstates are realized by bound states of D-branes wrapped along complex submanifolds, or in mathematical terms by "stable coherent sheaves". String dualities predict that suitable generating series of indices counting such BPS states have modular properties, although the mathematical origin of modularity is still mysterious. I will explain some recent progress in computing these BPS indices using relations to topological string theory and wall-crossing, and present strong evidence that modularity is indeed at work.

 

12:30-14:00 Lunch

 

14:00-15:00 Pietro Longhi (Uppsala University)

Title: Quiver structures of knot invariants, open strings, and recursion

Abstract: Generating series of HOMFLYPT polynomials colored by symmetric representations have been found to coincide with partition functions of motivic Donldson-Thomas invariants of symmetric quivers, after a suitable identification of variables. I will discuss an interpretation of this relation based on interactions of M2 branes mediated by an M5 brane. Invariance of this picture under deformations leads to a generalization of the knots-quivers correspondence corroborated by wall-crossing type phenomena associated with skein relations among M2 brane boundaries. If time permits, a generalization to multiple M5 branes will be discussed. Based on joint works with Ekholm and Kucharski and ongoing work with Ekholm.

 

15:15-16:15 Kantaro Ohmori (University of Tokyo)

Title: Non-supersymmetric Heterotic Branes

Abstract: The common statement that any consistent quantum gravity theory contains dynamical objects with all possible charges suggests that there are still a number of hitherto-unidentified branes in string theory. McNamara and Vafa proposed that such charges are classified by the bordism classes in the working EFT. In this talk I will describe some of those charges in heterotic string theories and then discuss plausible worldsheet descriptions of strings near the corresponding branes.

 

16:30-17:30 Eric Perlmutter (IPhT)

Title: AdS_3/RMT_2 Duality

Abstract: We introduce a framework for quantifying random matrix behavior of 2d CFTs and AdS quantum gravity. We present a 2d CFT trace formula, precisely analogous to the Gutzwiller trace formula for chaotic quantum systems. An analogy to Berry's diagonal approximation allows us to extract spectral statistics of individual 2d CFTs by coarse-graining, leading to a necessary and sufficient condition for a 2d CFT to display a linear ramp in its coarse-grained spectral form factor. Turning to gravity, AdS_3 torus wormholes are cleanly interpreted as diagonal projections of squared partition functions of microscopic 2d CFTs. The projection makes use of Hecke operators. The Cotler-Jensen wormhole of AdS_3 pure gravity is shown to be extremal among wormhole amplitudes: it is the minimal completion of the random matrix theory correlator compatible with Virasoro symmetry and SL(2,Z)-invariance. We call this MaxRMT: the maximal realization of random matrix universality consistent with the necessary symmetries. Completeness of the SL(2,Z) spectral decomposition as a trace formula allows us to factorize the Cotler-Jensen wormhole. The resulting microscopic partition function, Z_RMT, captures details of the spectrum of BTZ black hole microstates. Z_RMT may be interpreted as an AdS_3 half-wormhole of pure gravity. We discuss its implications for the dual CFT and modular bootstrap at large central charge.

 

• September 13 (Wed)

 

10:00-11:00 Kevin Costello (Perimeter Institute)

Title: Burns space and holography

 

11:15-12:15 Nick Dorey (DAMTP, Cambridge University)

Title: DLCQ, Holomorphic Blocks and Ultra-Spinning AdS Black Holes

 

12:30-14:00 Lunch

 

• September 14 (Thu)

 

10:00-11:00 Edward Witten (IAS, Princeton)

Title: A Background Independent Algebra in Gravity

Abstract: I consider the algebra of operators along the worldline of an observer as a starting point in constructing a background independent algebra of observables in quantum gravity.

 

11:15-12:15 G. Joaquin Turiaci (University of Washington)

Title: Spin-Statistics for Black Hole Microstates

Abstract: The gravitational path integral can be used to compute the number of black hole states for a given energy, or the free energy in a fixed temperature ensemble. In this article we explain how to use the gravitational path integral to compute the separate number of bosonic and fermionic black hole microstates. We do this by comparing the partition function with and without the insertion of (-1)^F. In particular we study a universal rotating black hole that contributes to the partition function in the presence of (-1)^F. We study this problem for black holes in asymptotically flat space and in AdS, putting constraints on the high energy spectrum of holographic CFTs (not necessarily supersymmetric). Finally, we analyze wormhole contributions to related quantities.

 

12:30-14:00 Lunch

 

14:00-15:00 S. Josephine Suh (KAIST)

Title: A holographic quantization scheme in gravity
Abstract: We discuss a background-independent, perturbative quantization scheme in gravity which when applied to the bulk action of JT gravity in AdS, produces joint distributions characterizing the quantum dynamics of the boundary of the theory. Our scheme could potentially apply to higher dimensions and general spacetimes. It supports and realizes the  principle  that the volume measure at a spacetime point should be operationally identified as a probability measure constrained by the dynamics of a quantum observable. Based on work in progress.
 

15:15-16:15 Yu-tin Huang (National Taiwan University)

Title: Bootstrapping perturbative string amplitudes

Abstract: In this talk, I will discuss how to incorporate the fact that the scattering amplitude has a worldsheet description into the general S-matrix bootstrap program. I will focus on open strings, whose worldsheet CFT four point function has universal monodromies associated with the massless factorization poles. These imply non-trivial monodromy relations amongst the S-matrix of different ordering. The latter, when combined with unitarity, carves out a more refined space of allowed EFT coefficients. When combined with maximal susy, the solution is shown to be unique with critical dimension 10, i.e. the Type-I superstring.

 

16:30-17:30 Ioana Alexandra Coman Lohi (Kavli IPMU)

Title: Mock modular forms as Z-invariants

Abstract: A new family of topological 3-manifold invariants has been proposed recently, with the property that they are q-series with integrality properties that allow categorification. They have a mathematical definition based on the data which specifies the associated 3-manifold, though this is of limited applicability and restricted to cases which satisfy a certain negativity condition. Aside from their relevance in topology, these invariants have proven to be of broad interest through a web of relations. Physically, they capture the partition functions of certain 3-dimensional SQFTs, while from a number theory perspective they provide examples of holomorphic quantum modular forms. Here I will discuss an underlying hidden symmetry of these invariants and how considerations of modularity can be leveraged to predict what these should be for manifolds not covered by their original definition, as well as the wider implications of these results.

 

• September 15 (Fri)

 

10:00-11:00 Gregory W. Moore (Rutgers)

Title: Finite Symmetries Of Field Theories From TQFT

Abstract: I will review some aspects of the paper ``Topological Field Theory In Quantum Field Theory,'' written with Dan Freed and Constantin Teleman. I will review some aspects of finite homotopy theories, which form the main source of examples in the paper, and attempt to give a talk complementary to the several excellent talks by Freed and Teleman already available online. This talk will be similar to the one I gave at the Oxford University Symmetry Seminar, Tuesday, May 23, 2023 via zoom.

 

11:15-12:15 Cyril Closset (University of Birmingham)

Title: Reading between the sections of Seiberg-Witten curves

Abstract: I will discuss the precise way in which rank-one Seiberg-Witten curves encode the global structure of 4d N=2 SQFTs. In particular, I will revisit the standard results for the pure su(2) gauge theory, the su(2) N=2* theory, and their 5d and 6d uplifts. In all these cases, the 4d one-form symmetries are encoded in the Mordell-Weil group of rational sections of the SW geometry, and gauging that symmetry can be understood in terms of isogenies along those sections. I will also touch upon the connection between global properties of the SW curve and the computation of BPS quivers for these theories. I may also discuss recent progress in the study of 5d and 6d BPS quivers.

 

12:30-14:00 Lunch

 

14:00-15:00 Daniele Dorigoni (Durham University)

Title: Modular Constraints on N=4 Yang-Mills / Type IIB Superstring Holography

Abstract: We will describe a surprisingly simple representation of a class of integrated correlation functions of four superconformal primaries in the stress tensor multiplet of N=4 supersymmetric Yang-Mills theory with arbitrary simple gauge group, G. We then present exact formulae for these integrated correlators which are manifestly invariant under GNO duality. For classical gauge groups, G=SU(N), SO(N), USp(2N), we derive the large-N expansions which are interpreted via holography in terms of the low-energy expansion of type IIB superstring amplitudes in AdS_5XS^5 or an orientifold thereof. In this way we recover the SL(2,Z)-invariant BPS interactions, arising in type IIB superstring amplitudes in the flat-space limit. From the asymptotic nature of the 1/N expansion we reconstruct non-perturbative contributions which holographically correspond to an infinite sum of (p,q)-string world-sheet instantons.

 

15:15-16:15 Sangmin Lee (SNU)

Title: Post-Minkowskian binary dynamics with spin and a massive twistor theory

Abstract: In recent years, ideas and techniques originating from scattering amplitudes have been successfully applied to the post-Minkowskian expansion of gravitational binary dynamics. When the (macroscopic) spin of the two bodies are taken into account, additional difficulties arise and the progress has been relatively slow. In this talk, we report two recent developments in spinning gravitational binary dynamics: global Poincaré algebra generators and a massive twistor worldline theory.