de Sitter Brane Gravity: from Close-Up to Panorama

TL;DR

This paper explicitly derives the graviton propagator on de Sitter branes in various 5D spacetimes, revealing novel features of brane gravity, including multiple graviton-like particles, scale-dependent Newton's constant, and localized gravity in Minkowski space.

Contribution

It provides a detailed analysis of the graviton propagator on de Sitter branes, uncovering new phenomena in brane gravity not seen in flat brane models.

Findings

Multiple graviton-like particles mediate gravity at different scales

Localized gravity can exist on de Sitter branes in Minkowski space

Kaluza-Klein modes influence 4D gravity on de Sitter branes in AdS

Abstract

We find explicitly the induced graviton propagator on de Sitter branes embedded in various five-dimensional spacetimes; de Sitter branes in AdS and Minkowski space are particular cases. By studying the structure of the momentum-space propagator, we are able to extract interesting physics, much of which is qualitatively different from that of flat branes. We find that 1) there can be a set of graviton-like particles which mediate brane gravity at different scales; 2) localized gravity can exist even on de Sitter branes in Minkowski space; 3) Kaluza-Klein modes also contribute to conventional 4-D gravity for de Sitter branes in AdS; and 4) Newton's constant can vary considerably with scale. We comment on the implications for the effective cosmological constant.