Department of Mathematics and Computer Science

Speaker: Giulia Muco, PhD student at QTC, who is going to talk about CFT and Large Charge Expansion. Here below you can find an abstract of the talk and the related reference.Abstract: Using the large-charge expansion, we prove a necessary condition for a CFT to exhibit conformal symmetry breaking, under the assumption that a continuous global symmetry is also broken on the moduli space: there must be a tower of charged local operators whose scaling dimensions are asymptotically linear in the charge. In supersymmetric theories with a continuous R-symmetry and a holomorphic moduli space, the existence of such a tower of operators follows trivially from a BPS condition: their scaling dimensions are then exactly linear in the R-charge. We illustrate the more general statement in several examples of three-dimensional N=1 CFTs, where the leading linear behavior receives nontrivial corrections. By considering a suitable scaling limit, we also relate the spectrum of states with large charge on the cylinder (isomorphic to local operators) to the spectrum of massive particles on the moduli space.Related reference: [download link]Location: The DIAS Meetingroom Nord (V24-410-2)You can also join via Zoom (passcode: 060379).The event is open to all.

Valentino Picotti defends his PhD thesis: Language Support for Microservices Development.Professor Jacopo Mauro will act as chairman at the defence.

Speaker: Guillaume Laplante-Anfossi (University of Southern Denmark) Abstract:Given a curved A-infinity algebra and a bounding cochain (a.k.a Maurer—Cartan element), one can twist the former by the latter to get a new A-infinity algebra where the curvature is zero. This uncurving procedure plays a central rôle in Floer theory, where Fukaya categories are naturally curved objects. The goal of this talk will be to give a universal characterization of the procedure, using the theory of operads: we will show that the operad cMC, whose algebras are curved A-infinity algebras endowed with a Maurer—Cartan element, together with its natural morphism to the A-infinity operad, is terminal in a certain comma category. This category does not contain the Maurer—Cartan equation, thus the theorem provides a way to « rediscover » it as the answer to a universal (algebraic) problem. This is joint work with Adrian Petr and Vivek Shende.

Speaker: Christoph Nega (Technical University of Munich)Abstract: In my talk, I will discuss Feynman Integrals which are the cornerstone for precision computations in perturbative physics ranging from quantum field theory to classical general relativity. The two main examples will be self-energies in quantum electrodynamics and the scattering of black holes in a perturbative treatment of general relativity. I will introduce the relevant concepts in the context of Feynman Integrals, as integration by parts relations, master integrals, canonical integrals, iterated integrals and others. Moreover, I will show that Feynman Integrals are related to period integrals on geometries, particularly on Calabi-Yau varieties. This knowledge can be used to compute them. At the end, I will discuss methods to numerically evaluate the Feynman Integrals appearing in my examples.

Speaker: Michael Borinsky The Institute for Theoretical Studies (ETH-ITS), Zürich Abstract:I will present new results on the asymptotic growth rate of the Euler characteristic of Kontsevich's commutative graph complex. These results imply the same asymptotic growth rate for the top-weight Euler characteristic of M_g, the moduli space of curves, due to a recent work by Chan, Galatius and Payne. Further, they establish the existence of large amounts of unexplained cohomology in this graph complex. I will explain the role of this graph complex from the perspective of M_g's cohomology.

Speaker: Meer Ashwinkumar University of Bern Abstract:TBA