Beschreibung
Ambitwistor-strings, BRST and the Penrose transform
Abstract: Ambitwistor strings are chiral sigma models whose targets are spaces of complex null geodesics in complexified space-times. Their correlation functions generate remarkable formulae for complete tree-level S-matrices of a variety of massless theories including gauge and gravity theories. This talk will focus on the geometry of the correspondences. It will exaplain how BRST descent implements the Penrose transform that encodes space-time fields into cohomology classes on ambitwistor space and how quantum consistency encodes the nonlinear field equations of gauge and gravity theories.