**Stable, ghost-free solutions in UV non-local gravity**

I consider higher derivative, UV modifications to GR. In particular, I will focus on a specific kind of string theory-inspired higher derivative gravity where one includes derivatives to all orders in the action. First, I will discuss how such a non-local theory of gravity admits stable, non-singular bouncing solutions in the absence of matter. Moreover, around this bouncing background, there exists only one propagating (and ghost-free) scalar mode, and no vector or tensor modes. Next, I will discuss the general analysis of scalar-vector-tensor perturbations in non-local gravity – in particular, I will show how non-local gravity is ghost-free around (A)dS and certain non-maximally symmetric backgrounds, and how certain (A)dS backgrounds have special physical spectra in that the propagating degrees of freedom are different from usual expectations.

Host: Kurt Hinterbichler

Zoom meeting ID: 999 3023 4812

For the password to access the meeting please contact one of us:

Kurt Hinterbichler: kjh92

Kara Farnsworth: kmf137

Ellen Rabe: exr223

Idit Zehavi: ixz6

at case.edu