Week 04.11.2017 – 12.11.2017


RG Flows Across Dimensions and Holography

Regular Seminar Nikolay Bobev (KU Leuven)

14:00 IC
room H503

Superconformal field theories placed in nontrivial background fields for the metric and the continuous global symmetries exhibit a rich web of RG flows across dimensions. I will discuss several examples of such flows and emphasize some of their universal features. In addition, I will employ non-perturbative tools such as 't Hooft anomaly matching, a-, F-, and c-extremization, and holography to gain a quantitative understanding of some aspects of these theories. Finally, I will discuss the relevance of these results for a microscopic understanding of the entropy of supersymmetric black holes and strings in AdS.

Twisted BRST quantization and localization in supergravity

Regular Seminar Sameer Murthy (King's College London)

13:15 KCL
room K4.31

Supersymmetric localization is a powerful technique to evaluate a class of functional integrals in supersymmetric field theories. It reduces the functional integral over field space to ordinary integrals over the space of solutions of the off-shell BPS equations. The application of this technique to supergravity suffers from some problems, both conceptual and practical. I will discuss one of the main conceptual problems, namely how to construct the fermionic symmetry with which to localize. I will show how a deformation of the BRST technique allows us to do this. I will then sketch a computation of the one-loop determinant of the super-graviton that enters the localization formula for BPS black hole entropy.


Integrable lattice models in the UV

Regular Seminar Luigi Tizzano (Uppsala U.)

14:00 QMW
room GO Jones 610

Integrable lattice models in 1+1 dimensions have been a topic of much fascination in physics since the early days of quantum mechanics. Recently, a work by Costello has offered a new perspective on these models based on a 4D topological gauge theory. An interesting aspect of this proposal is the close connection with 3D Chern-Simons theory and knot invariants. I will explain how to derive the 4D topological theory using string dualities and localization techniques for a 5D twisted super Yang-Mills theory. Finally, I will explain how this construction might relate to other appearances of Yangian symmetry which played a prominent role in AdS/CFT physics. This is a joint work in progress with Joe Minahan.