Schedule

Julian Kupka: Recent Advances in N=1, D=10 Supergravity

Abstract: I present the newest developments in N=1, D=10 supergravity. I review our generalised geometry component field framework and how we leveraged it to derive the higher fermion terms in the supergravity action and variations. Furthermore, I explain our findings of a novel canonical, torsion-free, non-flat connection on the field space in the treatment of spinorial fields. Lastly, I present the full Batalin-Vilkovisky (BV) formulation of N=1, D=10 supergravity coupled to super Yang-Mills - the first higher-dimensional BV supergravity action.

This talk is based on joint work with Fridrich Valach and Charles Strickland-Constable

Tancredi Schettini Gherardini: AInstein: Numerical Einstein Metrics through Machine Learning

Abstract: In this talk, we will discuss a very recent numerical scheme based on semi-supervised machine learning, "AInstein", which approximates generic Riemannian Einstein metrics on a specified manifold (arXiv:2502.13043). We will begin by reviewing the first applications of machine learning to find numerical Calabi-Yau metrics, and then present our generalisation of those approaches. We will summarise the results obtained with AInstein so far, which concern Einstein metrics on spheres of various dimensions. A long-standing open question in this context is the existence of non-round metrics on S^4 and S^5, for which our results provide heuristic numerical evidence against. Finally, we will comment on the numerous possible extensions and further applications of AInstein.

Silvia Georgescu: On symmetries and non-locality in warped AdS3 holography

Abstract: Warped AdS3 backgrounds provide set-ups to study holography beyond AdS and, in particular, holography for near-extremal Kerr black holes. In this talk, we focus on asymptotic symmetries of warped AdS3 backgrounds. It was recently argued that a (1,2) deformation of 2d CFTs, the JTbar deformation, captures features of the near-horizon geometry of near-extremal Kerr black holes and of certain warped AdS3 backgrounds. JTbar deformed CFTs have infinite dimensional symmetry algebras. In a basis in which the symmetry generators act non-locally, the algebra consists of two commuting copies of the Virasoro-U(1)KM algebra. We encounter the same symmetry algebra for certain warped BTZ backgrounds constructed in string theory.

Joseph Smith:  Non-Lorentzian Limits and Near-BPS Physics in String Theory

Abstract: BPS states are a key tool in our understanding of string theory and non-perturbative QFT. In this talk, I will discuss how excitations close to BPS bounds in brane worldvolume QFTs can be isolated using non-Lorentzian limits. These can be interpreted as limits of string theory, leading to bulk theories built around Newton-Cartan geometry. We will then see how to apply these limits to both sides of a holographic pair, leading to a proposed duality between non-Lorentzian CFTs and the dynamics of non-relativistic branes on curved Newton-Cartan backgrounds.