Title: A Tale of Two Limits

Speaker: Dr. Aditya Mehra, Edinburgh University

Meeting link: https://zoom.us/j/92116176467?pwd=NnZhcFZQbk5GRk5kbWdTWWJMcDlCQT09

Abstract: I will start with a review of conformal field theories, then give a detailed analysis of Galilean (non-relativistic) and Carrollian (ultra-relativistic) limits. The field theories in these limits will play a significant role in looking at physical systems such as the effective sector of Quantum electrodynamics, Quantum Hall effect, Superconductivity and Cosmology. I will tell you about the field theories that show a non-relativistic conformal structure in the Galilean limit. In this limit, the conformal structure manifested by the field theories becomes infinite-dimensional in D > 2, unlike in the relativistic counterparts. It will give a proper channel to work in non-relativistic physical systems. Similarly, in the Carrollian limit, I will show the invariance of a field theory under the infinite-dimensional Carrollian conformal algebra in D =4. Studying these field theories will set up a direct connection to asymptotically flat spacetimes at null infinity and the related BMS symmetries. It will also play a vital role in the geometries of null hypersurfaces such as black hole horizons.