A bstract We propose a new program for computing a certain integrand of scattering
amplitudes of four-dimensional gauge theories which we call the form factor integrand …

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 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 wrapping a certain ℂℙ 1. The backreaction of this defect …

We identify a diffeomorphism Lie algebra in the self-dual sector of Yang-Mills theory, and
show that it determines the kinematic numerators of tree-level MHV amplitudes in the full …

A bstract The question of whether the holomorphic collinear singularities of graviton
amplitudes define a consistent chiral algebra has garnered much recent attention. We …

A bstract The celestial Lw 1+∞ symmetries in asymptotically flat spacetimes have a natural
geometric interpretation on twistor space in terms of Poisson diffeomorphisms. Using this …

We study the subleading structure of asymptotically-flat spacetimes and its relationship to
the w1+∞ loop algebra of higher spin charges. We do so using both the Bondi–Sachs and …

Most nonlinear differential equations arising in natural sciences admit chaotic behaviour and
cannot be solved analytically. Integrable systems lie on the other extreme. They possess …

We consider holomorphic Poisson-BF theory on twistor space. Classically, this describes
self-dual Einstein gravity on space-time, but at the quantum level it is plagued by an …