Cornering Quantum Gravity

TL;DR

This paper explores the role of gauge symmetries and asymptotic symmetries in gravity, discussing the corner proposal and its implications for quantum gravity, with a focus on the BMS group and related phenomena.

Contribution

It introduces the corner proposal as a unified framework for understanding symmetries in gravity and discusses its impact on quantum gravity research.

Findings

BMS group as asymptotic symmetry of gravity at null infinity

Memory effects and soft theorems derived from symmetries

Extended phase space addresses charge integrability issues

Abstract

After introducing the covariant phase space calculus, Noether's theorems are discussed, with particular emphasis on Noether's second theorem and the role of gauge symmetries. This is followed by the enunciation of the theory of asymptotic symmetries, and later its application to gravity. Specifically, we review how the BMS group arises as the asymptotic symmetry group of gravity at null infinity. Symmetries are so powerful and constraining that memory effects and soft theorems can be derived from them. The lectures end with more recent developments in the field: the corner proposal as a unified paradigm for symmetries in gravity, the extended phase space as a resolution to the problem of charge integrability, and eventually the implications of the corner proposal on quantum gravity.