Galileon Radiation from a Spherical Collapsing Shell

TL;DR

This paper investigates Galileon radiation emitted during the collapse of a spherical shell, revealing two peaks in the radiated field and analyzing how the total energy scales with shell width.

Contribution

It provides the first detailed calculation of Galileon radiation from a collapsing shell within a cubic Galileon framework, highlighting the effects of Vainshtein suppression and shell thinness.

Findings

Radiated field exhibits two peaks traveling ahead of light fronts.

Total energy radiated scales as a power law with shell width.

Vainshtein suppression competes with thin-shell enhancement in emission.

Abstract

Galileon radiation in the collapse of a thin spherical shell of matter is analyzed. In the framework of a cubic Galileon theory, we compute the field profile produced at large distances by a short collapse, finding that the radiated field has two peaks traveling ahead of light fronts. The total energy radiated during the collapse follows a power law scaling with the shell's physical width and results from two competing effects: a Vainshtein suppression of the emission and an enhancement due to the thinness of the shell.