Theoretical Physics Wednesday Seminar: Matin Mojaza

Multiloop Soft Theorem for Gravitons and Dilatons in the Bosonic String

I will describe how one can write down closed-form expressions of closed-string amplitudes at any loop order in the bosonic string theory. I will then show that this makes it possible to extract the soft behavior of closed massless strings, and in particular establish a multiloop soft theorem through subsubleading order for the symmetrically polarized states, namely the graviton and dilaton, exposing nontrivial cancellations in the soft expansion at any loop order. Finally, if time permits, I will comment on a curious application at the tree level, which reveals a hidden symmetry of graviton amplitudes in ordinary Einstein gravity.