Perturbative soft graviton theorems in de Sitter spacetime

Abstract: We consider soft graviton scattering for a theory where Einstein's gravity is minimally coupled to a scalar field in the presence of a cosmological constant, i.e. in a background de Sitter space. Employing a perturbative expansion assuming a small cosmological constant, we compute the leading and subleading corrections to Weinberg's soft graviton amplitude in the static patch of de Sitter space. We observe similar universal features of the soft graviton amplitude as found in Bhatkar, Jain[J. High Energ Phys.55 (2023)] for the soft photons.