TBD

• Emil Bjerrum-Bohr

Room: U220

TBD

• Marta Orselli

Room: U220

Kerr Black Hole Dynamics from an Extended Polyakov Action

• Gang Chen

Room: U220 We examine a hypersurface model for the classical dynamics of spinning black holes. Under specific rigid geometric constraints, it reveals an intriguing solution resembling expectations for the Kerr Black three-point amplitude. We explore various generalizations of this formalism and outline potential avenues for employing it to analyze spinning black hole attraction.

TBD

• Nabha Shah

Room: U220

TBD

• Konstantin Wernli

Room: U220

Resurgence in Topological Quantum Field Theory

• William Mistegård

Room: U220 Resurgence is a method for summation of divergent power series. In recent years this have been succesfully applied to divergent series arising from pertubation theory in quantum field theory. I will illustrate this with the Witten-Reshetikhin-Turaev topological quantum field theory for a certain general class of three-manifold space-times. This is based on joint work with Andersen, Han, Li, Sauzin and Sun.

TBD

• Niels Obers

Room: U220

Boundary energy-momentum tensor for asymptotically flat spacetimes

• Emil Have

Room: U220 I will discuss the construction of a boundary energy-momentum tensor for asymptotically flat spacetimes. This involves rewriting Einstein's equations in a way that is covariant with respect to the Carrollian boundary geometry and turns part of the Einstein equations into Ward identities for the Carrollian energy-momentum tensor. I will also discuss holographic renormalisation for asymptotically flat spacetimes. This provides new insights into a putative holographic description of flat spacetime in terms of a boundary Carrollian conformal field theory.

Integrable corners in the space of Gukov-Witten defects

• Adam Chalabi

Room: U220 Integrability of planar N=4 super-Yang-Mills (SYM) theory enables exact computations of unprotected observables, even with the insertion of certain extended operators. While integrability techniques have been successfully applied to some supersymmetric domain walls and line defects, it is an open question whether there are any integrable surface defects in N=4 SYM theory. In this talk, I will examine a class of 1/2-BPS surface defects known as Gukov-Witten defects. I will argue that these defects are generically not integrable but they are likely to become integrable at a corner in parameter space. I will present closed-form factorised expressions for leading-order one-point functions of unprotected scalar operators, hinting at the possibility of finding an all-loop formula at this special point.

TBD

• Giulia Muco

Room: U220

TBD

• Alessia Platania

Room: U220

TBD

• Florian Seefeld

Room: U220

TBD

• Benjamin Jaeger

Room: U220

Gradient flow as a renormalization tool

• Antonio Rago

Room: U220 The Gradient Flow is a smoothing technique that has been extensively studied for its renormalization properties. When combined with the short flow-time expansion, it provides a renormalization scheme in which hadronic matrix elements on the lattice evolve with the flow time, suppressing ultraviolet (UV) divergences. In this scheme, some of the typical lattice challenges—such as operator mixing with lower-dimensional operators—are either avoided or relegated to the perturbative matching stage. I will begin by introducing the Gradient Flow methodology and provide an overview of the short flow-time expansion. I will then present our approach for determining two distinct classes of observables: (1) matrix elements of four-quark operators relevant to neutral meson mixing and meson lifetimes, and (2) renormalized quark masses.

The Brief Femtouniverse

• Peter Orland

Room: U220 No technique used to compute observables, such as the 1/N-expansion or the bootstrap method, is successful for QCD. A method which should work, at least in principle, is a semiclassical van-Vleck formula, applied to the femtouniverse: a small region of Euclidean space-time. This yields a renormalization-group transformation to a lattice model which should be a correct description of the continuum field theory at large distances. To test the method, we apply it to the (well-understood) O(3) nonlinear sigma model in two dimensions.