TY  - JOUR
AU  - Inomata, Keisuke
AU  - Kamionkowski, Marc
AU  - Kasai, Kentaro
AU  - Shakya, Bibhushan
TI  - Gravitational waves from particles produced from bubble collisions in first-order phase transitions
JO  - Physical review / D
VL  - 112
IS  - 8
SN  - 2470-0010
CY  - Ridge, NY
PB  - American Physical Society
M1  - PUBDB-2025-05696
M1  - arXiv:2412.17912
M1  - DESY-24-219
SP  - 083523
PY  - 2025
N1  - 12 pages + Appendices, 6 figures
AB  - We discuss a new source of gravitational waves (GWs) from first-order phase transitions. The collisions of bubbles of the new phase can efficiently produce particles that couple to the background field undergoing the transition, thereby transferring a significant fraction of the released vacuum energy into a distribution of inhomogeneous and dynamic particle populations that persist long after the bubbles have disappeared. We study the GWs produced by such particle distributions, showing that GWs arise from the quadrupolar anisotropy in the radiation emitted from the bubble collisions, and present a semianalytical calculation of the two-point correlation function for the associated energy distributions. We find that this new contribution can qualitatively modify the overall GW signal from such phase transitions, creating a distinct shift in the spectral slope at low frequencies that could be observed by future GW experiments. It is therefore important to take this new contribution into account for any transition where the background field has significant self-coupling or couplings to other fields that could lead to efficient particle production at bubble collision.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1103/k4s5-8zqy
UR  - https://bib-pubdb1.desy.de/record/642900
ER  -