Resumming fermion loops for inflationary gravity

Abstract

We compute the 1-loop contribution to the graviton self-energy from a loop of massless fermions on a general cosmological background. The result is used to quantum-correct the linearized Einstein equation on de Sitter background and work out 1-loop corrections to gravitational radiation and to the response to a point mass. The renormalization group is employed to sum these to all orders for as long as the de Sitter phase persists.