Lecture notes prepared for the 2021 SAGEX PhD School in Amplitudes hosted by the
University of Copenhagen August 10th through 13th. Topics covered include: the …

We review the role that infinite-dimensional symmetries arising at the boundary of
asymptotically flat spacetimes play in the context of the celestial holography program. Once …

A short, graduate-level synthesis of recent developments in theoretical physics, from a
pioneer in the field Lectures on the Infrared Structure of Gravity and Gauge Theory presents …

Gravity in 4 d asymptotically flat spacetime constitutes the archetypal example of a
gravitational system with leaky boundary conditions. Pursuing our previous analysis of …

A bstract We propose an extension of the BMS group, which we refer to as Weyl BMS or
BMSW for short, that includes super-translations, local Weyl rescalings and arbitrary …

A bstract We initiate a study of gravity focusing on generic null hypersurfaces, non-
perturbatively in the Newton coupling. We present an off-shell account of the extended …

In this paper we extract from a large-r expansion of the vacuum Einstein's equations a
dynamical system governing the time evolution of an infinity of higher-spin charges. Upon …

A bstract It is shown that black hole spacetimes in classical Einstein gravity are
characterized by, in addition to their ADM mass M, momentum\(\overrightarrow {P}\), angular …

A bstract We develop the covariant phase space formalism allowing for non-vanishing flux,
anomalies, and field dependence in the vector field generators. We construct a charge …

A bstract This is the first paper in a series devoted to understanding the classical and
quantum nature of edge modes and symmetries in gravitational systems. The goal of this …