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 explain how twistor theory represents the self-dual sector of four dimensional gravity in
terms of the loop group of Poisson diffeomorphisms of the plane via Penrose's non-linear …

A bstract We consider the twistor description of classical self-dual Einstein gravity in the
presence of a defect operator wrap** a certain ℂℙ 1. The backreaction of this defect …

A bstract We study celestial chiral algebras appearing in celestial holography, using the light-
cone gauge formulation of self-dual Yang-Mills theory and self-dual gravity, and explore also …

We show that self-dual gravity in Euclidean four-dimensional anti–de Sitter space (AdS 4)
can be described by a scalar field with a cubic interaction written in terms of a deformed …

A bstract Celestial holography has led to the discovery of new symmetry algebras arising
from the study of collinear limits of perturbative gravity amplitudes in flat space. We explain …

We consider all 1/2 BPS excitations of AdS× S configurations in both type-IIB string theory
and M-theory. In the dual field theories these excitations are described by free fermions …

We investigate the asymptotic symmetry algebra of (2+ 1)-dimensional higher spin, anti-de
Sitter gravity. We use the formulation of the theory as a Chern-Simons gauge theory based …

Many of the familiar integrable systems of equations are symmetry reductions of self-duality
equations on a metric or on a Yang-Mills connection. For example, the Korteweg-de Vries …

A bstract We study the connection of Moyal deformations of self-dual gravity and self-dual
Yang-Mills theory to chiral higher-spin theories, and also to deformations of operator …