Radiation from a Ddimensional collision of shock waves: Higherorder setup and perturbation theory validity
Abstract
The collision of two Ddimensional, ultrarelativistic particles—described in general relativity as AichelburgSexl shock waves—is inelastic. In firstorder perturbation theory, the fraction of the initial centerofmass energy radiated away was recently shown to be 1/21/D. Here, we extend the formalism to higher orders in perturbation theory, and derive a general expression to extract the inelasticity—valid nonperturbatively—based on the Bondi massloss formula. Then, to clarify why perturbation theory captures relevant physics of a strongfield process in this problem, we provide one variation of the problem where the perturbative framework breaks down: the collision of ultrarelativistic charged particles. The addition of charge, and the associated repulsive nature of the source, originates an extra radiation burst, which we argue to be an artifact of the perturbative framework, veiling the relevant physics.
 Publication:

Physical Review D
 Pub Date:
 April 2013
 DOI:
 10.1103/PhysRevD.87.084034
 arXiv:
 arXiv:1206.5839
 Bibcode:
 2013PhRvD..87h4034C
 Keywords:

 04.50.h;
 04.20.Cv;
 04.30.Db;
 04.50.Gh;
 Higherdimensional gravity and other theories of gravity;
 Fundamental problems and general formalism;
 Wave generation and sources;
 Higherdimensional black holes black strings and related objects;
 High Energy Physics  Theory;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology
 EPrint:
 21 pages, 3 figures