Arthur Lipstein is a Postdoctoral Research Associate at University of Hamburg/DESY.

Ambitwistor string theories are a family of chiral (holomorphic) string theories whose target space is the space of complexified null geodesics in a general space-time. Like conventional strings, they are critical in 10 dimensions and describe supergravity, but unlike conventional strings, they do not admit a tower of higher massive modes (and are correspondingly not thought to be ultraviolet finite). They provide a natural generalization of the twistor-strings of Witten, Berkovits and Skinner to arbitrary dimension and their correlators give rise to the beautiful formulae for gravitational and Yang-Mills scattering amplitudes in all dimensions recently discovered by Cachazo, He and Yuan (CHY). Ambitwistor strings were also used to obtain new formulae in four dimensions by the authors of this article.

In a recent series of papers, Strominger and Continue reading →