`2020-10-26 15:30:00``2020-10-26 16:03:00``High Energy Physics Seminar - Shubham Maheshwari (University of Groningen) - "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. Zoom link: https://osu.zoom.us/j/98489863235?pwd=VHd1WmQ0NGRybkZiNHl5cG5nK0JTUT09 Password: 995020``Zoom seminar``OSU ASC Drupal 8``ascwebservices@osu.edu``America/New_York``public`

`2020-10-26 15:30:00``2020-10-26 16:03:00``High Energy Physics Seminar - Shubham Maheshwari (University of Groningen) - "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. Zoom link: https://osu.zoom.us/j/98489863235?pwd=VHd1WmQ0NGRybkZiNHl5cG5nK0JTUT09 Password: 995020``Zoom seminar``Department of Physics``physics@osu.edu``America/New_York``public`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.

Zoom link: https://osu.zoom.us/j/98489863235?pwd=VHd1WmQ0NGRybkZiNHl5cG5nK0JTUT09

Password: 995020