Title: Extracting bigravity from string amplitudes

Abstract: The origin of the graviton from string theory is well understood: it corresponds to a massless state in closed string spectra, whose low-energy effective action, as extracted from string scattering amplitudes, is that of Einstein-Hilbert. In this talk, based on arXiv:2106.04614 [arxiv.org], we will discuss the possibility of a such a string-theoretic emergence of ghost-free bimetric theory, a recently proposed extension of general relativity that involves two dynamical metrics and which around particular backgrounds propagates the graviton and a massive spin-2 field, with the latter having been put forward as a viable dark matter candidate.

Talk – Video

Talk – Slides