Brane-Induced Gravity's Shocks

TL;DR

This work constructs exact gravitational field solutions for a relativistic particle localized on a tensional brane in brane-induced gravity and discovers a new nonperturbative channel for energy emission into the bulk from the self-inflating [corrected] branch, when gravity is modified at the de Sitter radius.

Abstract

We construct exact gravitational field solutions for a relativistic particle localized on a tensional brane in brane-induced gravity. They are a generalization of gravitational shock waves in 4D de Sitter space. We provide the metrics for both the normal branch and the self-inflating branch DGP braneworlds, and compare them to the 4D Einstein gravity solution and to the case when gravity resides only in the 5D bulk, without any brane-localized curvature terms. At short distances the wave profile looks the same as in four dimensions. The corrections appear only far from the source, where they differ from the long distance corrections in 4D de Sitter space. We also discover a new non-perturbative channel for energy emission into the bulk from the self-inflating branch, when gravity is modified at the de Sitter radius.