## Albrecht Klemm (Uni-Bonn) “On the period geometry of Calabi-Yau fourfolds and landscaping by fluxes” (String Seminars)

## Netta Engelhardt (UCSB) “Quantum Extremal Surfaces for Holographic Entanglement Entropy” (String Seminars)

## Zach Fisher (UC Berkeley) “Entropy on null surfaces and the covariant bound” (String Seminars)

## Anindya Dey (U. of Texas) “Field Theory on Gibbons-Hawking Spaces” (String Seminars)

Abstract: The IR Lagrangian of an N=2 supersymmetric gauge theory compactified on R^3 x S^1, around a generic point of its moduli space, is a 3d sigma model with a hyperkahler target space. We consider a related problem of constructing the IR Lagrangian of an N=2 theory on a special family of circle fibrations over R^3 — namely Gibbons-Hawking spaces. … Read More

## Shira Chapman (Tel Aviv U.) “Lifshitz Field Theories, Anomalies and Hydrodynamics” (String Seminars)

## Andrew Waldron (UC Davis) “Is quantum gravity a Chern-Simons theory?” (String Seminars)

## Brian Swingle (Stanford) “The Information Theoretic Interpretation of the Length of a Curve” (String Seminars)

Abstract: In the context of holographic duality with AdS3 asymptotics, the Ryu-Takayanagi formula states that the entanglement entropy of a subregion is given by the length of a certain bulk geodesic. The entanglement entropy can be operationalized as the entanglement cost necessary to transmit the state of the subregion from one party to another while preserving all correlations with a … Read More

## João Miguel Vieira Gomes (DAMTP) “Quantum supergravity and exact holography” (String Seminars)

Abstract: I will present recent results on the computation of finite N effects in supergravity in the context of AdS2/CFT1 and AdS4/ABJM holography. I will show how to use localisation to compute all perturbative and nonperturbative charge corrections to the entropy of supersymmetric black holes including complicated number theoretic objects called Kloosterman sums. These are essential to recover an integer … Read More

## Falk Haßler (LMU Munich) “String Geometry Beyond the Torus” (String Seminars)

Abstract: Besides propagating in target space like a point particle, a closed string is also able to wind around non-contractible circles. A direct consequence thereof is T-duality. In the textbook example, it identifies the closed string dynamics on a large and a small circle by interchanging its winding and momentum modes. Patching a background by such dualities clearly goes beyond … Read More

## Ron Donagi (UPen) “Super Riemann surfaces and some aspects of superstring perturbation theory” (String Seminars)

We study various aspects of supergeometry, including obstruction, Atiyah, and super-Atiyah classes. This is applied to the geometry of the moduli space of super Riemann surfaces and to its Deligne-Mumford compactification. For genus greater than or equal to 5, this moduli space is not projected (and in particular it is not split): it cannot be holomorphically projected to its underlying … Read More