Vacuum bubble collisions: from microphysics to gravitational waves
arXiv:2107.05657 · doi:10.1103/PhysRevD.104.075039
Abstract
We comprehensively study the effects of bubble wall thickness and speed on the gravitational wave emission spectrum of collisions of two vacuum bubbles. We numerically simulate a large dynamical range, making use of symmetry to reduce the dimensionality. The high-frequency slope of the gravitational wave spectrum is shown to depend on the thickness of the bubble wall, becoming steeper for thick-wall bubbles, in agreement with recent fully 3+1 dimensional lattice simulations of many-bubble collisions. This dependence is present, even for highly relativistic bubble wall collisions. We use the reduced dimensionality as an opportunity to investigate dynamical phenomena which may underlie the observed differences in the gravitational wave spectra. These phenomena include `trapping', which occurs most for thin-wall bubbles, and oscillations behind the bubble wall, which occur for thick-wall bubbles.
22 pages, 12 figures, 1 table
References in corpus (9)
- Gravitational Wave Production by Collisions: More Bubbles
- Gravitational wave energy budget in strongly supercooled phase transitions
- On the validity of perturbative studies of the electroweak phase transition in the Two Higgs Doublet model
- Bubble wall velocity: heavy physics effects
- Classical Decay Rates of Oscillons
- Gravitational Radiation from First-Order Phase Transitions
- Numerical Investigations of Oscillons in 2 Dimensions
- Gravitational wave spectra from oscillon formation after inflation
- Observer dependence of bubble nucleation and Schwinger pair production