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 …

The operator product expansion (OPE) on the celestial sphere of conformal primary gluons
and gravitons is studied. Asymptotic symmetries imply recursion relations between products …

Recent attempts at the construction of holography for asymptotically flat spacetime have
taken two different routes. Celestial holography, involving a two dimensional (2D) conformal …

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 four-dimensional S-matrix is reconsidered as a correlator on the celestial
sphere at null infinity. Asymptotic particle states can be characterized by the point at which …

We argue that, in a theory of quantum gravity in a four dimensional asymptotically flat
spacetime, all information about massless excitations can be obtained from an infinitesimal …

Asymptotic particle states in four-dimensional celestial scattering amplitudes are labeled by
their SL (2, C) Lorentz/conformal weights (h, h¯) rather than the usual energy-momentum …

A bstract We explore the logarithmic terms in the soft theorem in four dimensions by
analyzing classical scattering with generic incoming and outgoing states and one loop …

A bstract We show that a holographic description of four-dimensional asymptotically locally
flat spacetimes is reached smoothly from the zero-cosmological-constant limit of anti-de …

Carrollian field theories at the classical level possess an infinite number of space-time
symmetries, namely the supertranslations. In this article, we inquire whether these …