10.1088/0264-9381/20/11/325
Hossenfelder, S
S
Hossenfelder
Schwarz, Dominik
Dominik
Schwarz0000-0003-2413-0881
Greiner, W
W
Greiner
Particle production in time-dependent gravitational fields: the expanding mass shell
IOP Publishing
2003
2011-08-29T09:40:43Z
2018-07-24T13:01:21Z
journal_article
https://pub.uni-bielefeld.de/record/2323241
https://pub.uni-bielefeld.de/record/2323241.json
0264-9381
gr-qc/0210110
We compute the production of particles from the gravitational field of an expanding mass shell. Contrary to the situation of Hawking radiation and the production of cosmological perturbations during cosmological inflation, the example of an expanding mass shell has no horizon and no singularity. We apply the method of 'ray-tracing', first introduced by Hawking, and calculate the energy spectrum of the produced particles. The result depends on three parameters: the expansion velocity of the mass shell, its radius and its mass. Contrary to the situation of a collapsing mass shell, the energy spectrum is non-thermal. Invoking time reversal we reproduce Hawking's thermal spectrum in a certain limit.