Black holes, naturalness and the renormalization group

• Julio Parra-Martinez (IHES)

Room: Salle Itzykson test

Worldlines in a plasma

• Leonardo de la Cruz (IPhT CEA-Saclay)

Room: Salle Itzykson

Nonlinear gravitational memory from scattering amplitudes

• Carlo Heissenberg

Room: Salle Itzykson

L-functions and Randomness in 2d CFTs

• Eric Perlmutter (IPhT CEA-Saclay)

Room: Salle Itzykson

Static Quadratic Love Numbers

• Filippo Vernizzi (IPhT - CEA Saclay)

Room: Salle Itzykson

Conformal collider bootstrap

• Alexander Zhiboedov (CERN)

Room: Salle Itzykson

Resuming perturbative invariants of hyperbolic knots

• Veronica Fantini (Université Paris-Saclay)

Room: Salle Itzykson Given a hyperbolic knot, the Andersen-Kashaev state integrals are convergent integrals associated with certain triangulations of the knot complement. Their asymptotic expansion is a perturbative topological invariant conjectured to be resurgent and Borel summable by Garoufalidis, Gu, and Mariño. Motivated by resuming these perturbative invariants, we define a new homology theory that allows us to construct exponential period integrals, whose asymptotic expansion recovers the original divergent series. In this talk, I will explain the main ideas of our construction, and time permitting, how they can be generalized to study similar classes of exponential period integrals (e.g. Feynman integrals in the Baikov representation). Based on a joint project with C. Wheeler (arXiv:2410.20973) and our ongoing work together with J. E. Andersen and M. Kontsevich.

Large colour Wilson loops in N=4 SYM and Fredholm determinants

• Victor Mishnyakov (Nordita)

Room: Salle Itzykson

Correlation functions in N=2 superconformal long quiver theories

• Alessandro Testa (IPhT CEA-Saclay)

Room: Salle Itzykson

Exact Three-Point Functions in N=2 Superconformal Field Theories

• Gwenael Ferrando (Bonn)

Room: Salle Itzykson We propose an integrability approach for planar three-point functions at finite coupling in N=2 superconformal field theories obtained as Z_K orbifolds of N=4 super Yang-Mills (SYM). Generalising the hexagon formalism for N=4 SYM, we reproduce the structure constants of Coulomb branch operators, previously obtained by supersymmetric localisation, as exact functions of the 't Hooft coupling. Our analysis explains the common physical origin of Fredholm kernels in integrability and localisation, and hints at structures after the resummation in the hexagon formalism. This talk is based on arXiv:2503.07295 written with S. Komatsu, G. Lefundes, and D. Serban.

Another 8 Loop Form Factor in Planar N=4 SYM

• Lance Dixon (CERN/SLAC)

Room: Salle Itzykson

Origin limits of large-charge correlators in planar N=4 SYM

• Benjamin Basso (Laboratoire de Physique de l'École Normale Supérieure)

Room: Salle Itzykson

Bootstrapping six-point Yang-Mills amplitudes

• Dmitry Chicherin (LAPTh, CNRS)

Room: Salle Itzykson

Positivity Properties of Scattering Amplitudes

• Prashanth Raman (MMPI)

Room: Salle Itzykson Positivity properties in quantum field theory (QFT) are often associated with fundamental principles such as unitarity and causality. Yet, in many cases, these properties arise from deeper mathematical structures. In this talk, we explore an infinite set of positivity constraints obeyed by certain amplitudes—and related observables—that go beyond conventional expectations. Specifically, we highlight regions where these quantities and all of their signed derivatives are positive, a striking behavior known in mathematics as complete monotonicity. We begin by introducing completely monotone (CM) functions and their key properties, including their integral representations. We then demonstrate how fundamental objects in QFT, such as scalar Feynman integrals, exhibit this property. Building on this, we present evidence that a variety of observables—such as Coulomb branch amplitudes, the cusp anomalous dimension, and remainder functions in planar 𝑁=4 super Yang–Mills theory—exhibit complete monotonicity across multiple perturbative orders. We further show that some observables belong to an even more restricted subclass of CM functions, known as Stieltjes functions, which in particular allows for very good approximations of these observables using rational-functions. We conclude by outlining potential applications of these constraints to the numerical bootstrap of Feynman integrals and to the ongoing study of positive geometries in quantum field theory.

The use of conformal Regge theory for high-order perturbative calculations

• Leonid Shumilov (University of Hamburg)

Room: Salle Itzykson