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High Energy Physics Seminar - Shubham Maheshwari (University of Groningen) - "Stable, Ghost-free Solutions in UV Non-local Gravity"

Shubham Maheshwari - University of Groningen, 10/28/20 High Energy seminar speaker
October 26, 2020
3:30PM - 4:03PM
Zoom seminar

Date Range
Add to Calendar 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