Public holiday

Title:   Fuzzballs: Black Hole Microstructure in String Theory
Speaker:   Emil Martinec

Title:   Universality classes of turbulence.

Abstract:   The question is not only how the state depends on symmetries and types of interaction,  but also on ways of excitation and dissipation. We have started to answer this question using alternatively weak coupling or large-N limits.

Conference webpage: https://indico.global/event/14044/overview

Title:   Fuzzballs: Black Hole Microstructure in String Theory
Speaker:   Emil Martinec
Abstract:   N/A

Title:   Paths to Quantum Cellular Automata    

Abstract:   Quantum Cellular Automata (QCA) are automorphisms of the algebra of local observables of quantum lattice systems that strictly preserve locality. They can serve both as entanglers of invertible states and as realizations of locality-preserving symmetry actions on observables. Conjecturally, QCA define a generalized cohomology theory, analogous to invertible phases. In this talk, I will present a classification of all translation-invariant QCA modulo shallow quantum circuits and translations, together with the associated Ω-spectrum. I will then describe a path to the “space of QCA”  by constructing an ∞-groupoid of QCA by analogy with the path-groupoid of a topological space. Within this framework, all possible lattice anomalies of global symmetry actions appear naturally from homotopy classes of maps from BG to that groupoid.

Title:   Fuzzballs: Black Hole Microstructure in String Theory
Speaker:   Emil Martinec
Abstract:   N/A

Speaker:   Robert Bryant, Duke University
Title:   Curvature-homogeneous hypersurfaces in space forms

Abstract:

In a recent work with L. Florit and W. Ziller, we completed the classification of curvature-homogeneous hypersurfaces in spaces of constant curvature. It was a surprise to find that, in the previously unsolved cases, there exists an exotic family of solutions that are not homogeneous as hypersurfaces, and it turns out that a variety of techniques are needed to understand them fully. I’ll begin by surveying the history of the problem, starting with the classic works of É. Cartan and H.-F. Münzer on isoparametric hypersurfaces, as well as more recent work on the isoparametric case and the more general curvature-homogeneous problem. Then I’ll explain the ideas and techniques (including using symbolic calculation software and Gröbner bases) that led to the resolution of the final cases (and why these were needed).

Speaker:   James Waterman
Title:   TBA