Skip to main content
DA / EN

Kommende arrangementer på

Center for Kvantematematik

Campusvej 55, Odense M

26.02.2024

15:00 - 16:00

QM Research Seminar: The Epstein-Glaser-Brunetti-Fredenhagen renormalisation for pseudodifferential operators

26 feb

Speaker: Arne Hofmann (University of Göttingen) Abstract: In 2000, Brunetti and Fredenhagen built on the causal perturbation theory of Epstein and Glaser to prove the renormalisability of scalar field theory on curved spacetimes. Their construction was criticized in subsequent publications by Hollands and Wald for failing to satisfy local covariance. I will show that with appropriate modifications, local covariance can be achieved in the Brunetti-Fredenhagen construction, for distributions which resemble (classical) pseudodifferential operators. The crucial feature of such distributions is the existence of uniform asymptotic expansions.

Læs mere

Campusvej 55, Odense M

29.02.2024

15:00 - 16:00

QM Research Seminar: Numbers and Functions in Quantum Field Theory: From Algebraic Geometry to Precision Physics

29 feb

Speaker: Matthias Wilhelm (Niels Bohr Institute) Abstract: In this talk, I will give an overview of the numbers and functions that occur in Quantum Field Theory, which are relevant for the calculation of precision predictions for collider and gravitational-wave experiments. In the simplest cases, the functions that occur are multiple polylogarithms, generalizations of logarithms. They are by now very well understood and allow us to reach precision that would be impossible using any other method; in one case up to the eighth subleading order in perturbation theory! In the next cases, we encounter elliptic integrals, where much progress was made in recent years. Beyond these, we encounter an infinite zoo of further functions involving integrals over Calabi-Yau manifolds, which are currently being explored.

Læs mere

Campusvej 55, Odense M

21.03.2024

15:00 - 16:00

Quantum & Crémant: TBA

21 mar

Speaker: Astrid Eichhorn Department of Physics, Chemistry and Pharmacy University of Southern Denmark Abstract: TBA

Læs mere

Campusvej 55, Odense M

03.04.2024

15:00 - 16:00

QM Research Seminar: Fusion categories as (quantum) symmetries: stability conditions and Morita duality

3 apr

Speaker: Edmund Heng (Institut des Hautes Études Scientifiques) Abstract: Classically, finite symmetries are captured by the action of a finite group. Moving to the quantum world, one has to allow for (possibly non-invertible) quantum symmetries — these are instead captured by the action of a more general algebraic structure, known as a fusion category. Such quantum symmetries are actually ubiquitous in mathematics; for example, given a category with an action of a finite group G (e.g. rep(Q), Coh(X) etc.), its G-equivariant category has instead the action of the category of representations rep(G), where rep(G) has the structure of a fusion category (and is not just a group when G is non-abelian). The aim of this talk is to introduce fusion categories and discuss their role as “quantum symmetries” in relation to Bridgeland’s stability conditions. We first introduce a generalised notion replacing “G-invariant stability conditions” in the setting of a triangulated category equipped an action of a fusion category C, which we will “C-equivariant stability conditions”. The first result is that these stability conditions form a closed submanifold of the stability manifold, just as the G-invariant stability conditions do. Moreover, given a triangulated D with a G-action, so that its G-equivariant category D^G has a rep(G)-action, we will see the following (Morita) duality result for stability conditions: the complex manifold of G-invariant stability conditions (associated to D) is homeomorphic to the complex manifold of rep(G)-equivariant stability conditions (associated to D^G). If time allows, I will discuss other more “exotic” actions of fusion categories on triangulated categories, and possibly its relation to Coxeter theory. This is part of joint work with Hannah Dell and Anthony Licata.

Læs mere

Center for Kvantematematik Institut for Matematik og Datalogi Syddansk Universitet

  • Campusvej 55
  • Odense M - DK-5230
  • Telefon: +45 6550 7359

Sidst opdateret: 20.02.2024