Brane-Induced Gravity's Shocks

TL;DR

This paper derives exact gravitational shock wave solutions in brane-induced gravity models, comparing different branches and revealing new energy emission channels into the bulk, with implications for gravity's behavior at various scales.

Contribution

It provides the first exact solutions for gravitational shock waves in brane-induced gravity, including the normal and self-inflating branches, and uncovers a novel energy emission mechanism into the bulk.

Findings

Wave profiles match 4D gravity at short distances.

Corrections to gravity appear only at large distances.

Discovered a non-perturbative energy emission channel into the bulk.

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.