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 …

We show that a 3D sourced conformal Carrollian field theory has the right kinematic
properties to holographically describe gravity in 4D asymptotically flat spacetime. The …

A bstract All 4D gauge and gravitational theories in asymptotically flat spacetimes contain an
infinite number of non-trivial symmetries. They can be succinctly characterized by …

By virtue of the Noether theorems, the vast gauge redundancy of general relativity provides
us with a rich algebra of boundary charges that generate physical symmetries. These …

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 …

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 The isomorphism between the (extended) BMS 4 algebra and the 1+ 2D Carrollian
conformal algebra hints towards a co-dimension one formalism of flat holography with the …

Celestial holography proposes a duality between the gravitational $\mathcal {S} $-matrix
and correlators in a conformal field theory living on the celestial sphere. In this white paper …

A bstract The surface charge algebra of generic asymptotically locally (A) dS 4 spacetimes
without matter is derived without assuming any boundary conditions. Surface charges …