Korea-France Joint Workshop on String Theory

Liste des Contributions

1. From Z to a: Universal Constraints on Rotating Partition Functions and Conformal Anomalies

Shiraz Minwalla (TIFR Mumbai)

15/09/2026 10:00

The free energy of any CFT, $ \ln Z(\beta; \omega_i)$, admits two expansions: high temperature ($\beta \rightarrow 0$) and fast rotation ($\omega_i \rightarrow 1$). We demonstrate that locality of the thermal effective action forces $\ln Z$ to take a simple analytic form at all orders in the high temperature expansion, and further imposes an infinite number of sharp relations on the...

2. Conformal Colliders: Strings, Membranes and the Bootstrap

Robin Karlsson (University of Oxford)

15/09/2026 11:30

I will discuss the energy-energy correlator (EEC) in maximally supersymmetric conformal field theories. In four-dimensional $N=4$ SYM, I will describe how nonperturbative bootstrap methods can be used to obtain bounds on this collider observable at finite coupling. I will then discuss the same collider setup in theories dual to M-theory, notably three-dimensional $N=8$ ABJM theory and...

3. A Melonic Quantum Mechanical Model Without Disorder

Anna Biggs (Princeton University)

15/09/2026 14:00

I will describe a quantum mechanical model involving $N$ interacting fermions without disorder that has a large $N$ melonic expansion. In particular, it has the same Schwinger-Dyson equations and low energy physics as the $\mathcal{N} = 2$ supersymmetric SYK model. The model is SU(2) invariant, and the supercharge involves the SU(2) 3j symbol. I will conceptually explain why the model has a...

4. Sum over Topologies, Symmetry-Based Ensembles of 2d CFTs, and a Solvable Model of 3d Gravity

Anatoly Dymarsky (University of Kentucky)

15/09/2026 15:15

Two of the central open problems in three-dimensional quantum gravity are how to sum over all 3d topologies, which is necessary for self-consistency, and how to define the dual ensemble, which is believed to include all CFTs at large central charge.

In this talk I present a model of 3d gravity in which both of these questions can be addressed explicitly. The model, formulated within the...

5. Open and Closed Triangulations of 3d Gravity

Diandian Wang (Harvard University)

15/09/2026 16:45

Virasoro TQFT provides a powerful framework for computing amplitudes in quantum three-dimensional gravity. Conformal Turaev–Viro theory offers a closely related, triangulation-based formulation of the same underlying structure. We develop a BCFT perspective on both theories and give an alternative derivation of the relation between them.

8. Congratulatory Remarks by the Korean Embassy to France

Mme Hyekyoung Jung (Attachée scientifique, ambassade de Corée en France)

15/09/2026 17:45

6. Euclidean Wormholes, Quantum Chaos, and the Factorization Puzzle

Hong Liu (Massachusetts Institute of Technology)

16/09/2026 10:00

I propose a resolution of the factorization puzzle in AdS/CFT based on quantum-chaotic behavior in the large-N limit. In this framework, Euclidean wormhole contributions admit a boundary description within a single quantum theory, without invoking an ensemble average.

7. Connectivity and Spacetime Emergence

Elliott Gesteau (MIT & Harvard CMSA)

16/09/2026 11:30

Recent developments in holography have put forward examples of spacetimes with disconnected closed components. In this talk, I will present some insights that have been obtained from attempts to understand the holographic emergence of such spacetimes, and in particular, their connection to the subtle nature of some large-N observables in AdS/CFT.

9. EFTs with Symmetric Moduli Spaces: the Landscape and the Swampland

Mariana Graña (IPhT, CEA Saclay)

16/09/2026 14:00

We will show that effective theories with symmetric moduli spaces satisfy the Swampland Distance Conjecture, namely for any infinite distance limit there is a tower of states becoming exponentially light. The mass decay rates of the states are entirely encoded in the Weyl polytope of the representation under which they transform. Imposing these rates to be those of either tensionless strings...

10. Towards Explicit Bounds in Supergravity

Seung-Joo Lee (Yonsei University)

16/09/2026 15:15

Effective theories that admit a UV completion into quantum gravity are subject to a set of universal consistency constraints. Those constraints can sometimes lead to explicit, uniform bounds on concrete physical quantities of the effective theories. In the context of supersymmetric string compactifications, such physical bounds in turn translate into bounds on corresponding geometric...

11. Anomalies and the Structure of String Theory

Matilda Delgado (Harvard University & MPI Munich)

16/09/2026 16:45

I will discuss recent progress in understanding non-supersymmetric string theory using anomalies. I will focus on two complementary aspects: anomalies in spacetime and anomalies on the worldsheet. Spacetime anomalies provide constraints on candidate theories and offer evidence that certain non-supersymmetric string constructions are well-defined at the quantum level. Worldsheet anomalies, on...

12. Microstate Counting from Defects in de Sitter

Jan de Boer (University of Amsterdam)

17/09/2026 10:00

I will explain how one can obtain de Sitter entropy by counting states composed of thin shells and end of the world branes, and what assumptions have to be made to make this work. If time permits, some other aspects of thin shells will be discussed as well.

13. Curiosities of Superstring Perturbation Theory at One Loop

Mukund Rangamani (QMAP, UC Davis)

17/09/2026 11:30

I will discuss aspects of superstring perturbation theory at one loop, i.e., on a toroidal worldsheet, focusing on zero and one-point functions.
Specifically, I will exhibit some non-trivial aspects in both critical and non-critical string theories, owing to the presence of Ramond zero modes when the spin structure is odd. String dualities will prove a helpful guide in sorting out the...

14. Worldsheet Duals for One Matrix Models

Rajesh Gopakumar (ICTS, Bangalore)

17/09/2026 14:00

I will describe a concrete closed string dual to a general interacting Hermitian one matrix model, away from the double scaling limit. The correspondence holds for all genus and to all orders in the 't Hooft coupling(s). The worldsheet theory consists of a supersymmetric B-twisted Landau--Ginzburg model coupled to 2d topological gravity. A precise dictionary between traces of the matrix and...

15. Equivariant Volumes and Holography

Alberto Zaffaroni (Milano Bicocca University)

17/09/2026 15:15

I discuss applications of equivariant localization to holography, emphasizing the special role played by the equivariant volume of the internal or spacetime manifold. In particular, I describe the localization of the on-shell action in five-dimensional gauged supergravity for solutions with nontrivial topology and the resulting predictions for a variety of black objects in AdS5 still to be found.

16. Non-Unitary Bulk-Boundary Correspondence

Dongmin Gang (Seoul National University)

17/09/2026 16:45

I will review recent developments in extending the bulk–boundary correspondence between three-dimensional topological quantum field theories (TQFTs) and two-dimensional rational conformal field theories (RCFTs) to the non-unitary setting. This correspondence can be viewed as a generalization of the celebrated Chern–Simons/Wess–Zumino–Witten (CS/WZW) correspondence. Remarkably, the...

17. Talk

Stefano de Angelis (IPhT, CEA Saclay)

18/09/2026 10:00

18. Locality, Higher Symmetries, and Anomalies: an Operator-Algebraic Approach

Anton Kapustin (Caltech & IHES)

18/09/2026 11:30

In the usual Euclidean path-integral picture, higher symmetries are represented by invertible topological defects, and ’t Hooft anomalies are described by anomaly inflow from a topological action in one dimension higher. Is there a corresponding construction that starts directly from the algebra of local operators and its symmetries? To address this question, I will describe a mathematically...

19. A First Look at Magnusian Bootstrap

Jung-Wook Kim (CERN)

18/09/2026 14:00

The Magnus series is the formal expansion for the logarithm of the S-matrix, similar to the Dyson series being the formal expansion for the S-matrix itself. Magnus amplitudes refer to the matrix elements of the log of the S-matrix. As is well known, string theory has its roots in the bootstrap programme. What can we learn by bootstrapping Magnus amplitudes? I will report on some preliminary...

20. Talk

Anna Wolz (UCLA)

18/09/2026 15:15

21. Gravitational Scattering at Null Infinity: Asymptotics, BMS Symmetries, Angular Momentum, and Peeling Violation

Thibault Damour (IHES)

18/09/2026 16:45

We present some results about the asymptotic structure of the gravitational field emitted during the gravitational scattering of two
point masses. This problem has recently been investigated from several complementary angles: the Multipolar Post-Minkowskian formalism,
Effective-Field-Theory approaches, Soft theorems, Celestial Holography, and extension of the Bondi-Metzner-Sachs (BMS)...