Phase transitions in an expanding universe: stochastic gravitational waves in standard and non-standard histories

By Huai-Ke Guo, Kanu Sinha, Daniel Vagie, G. White. Journal of Cosmology and Astroparticle Physics, 2020

262 citations recorded by the source corpus.

We undertake a careful analysis of stochastic gravitational wave production from cosmological phase transitions in an expanding universe, studying both a standard radiation as well as a matter dominated history. We analyze in detail the dynamics of the phase transition, including the false vacuum fraction, bubble lifetime distribution, bubble number density, mean bubble separation, etc., for an expanding universe. We also study the full set of differential equations governing the evolution of plasma and the scalar field during the phase transition and generalize results obtained in Minkowski spacetime. In particular, we generalize the sound shell model to the expanding universe and determine the velocity field power spectrum. This ultimately provides an accurate calculation of the gravitational wave spectrum seen today for the dominant source of sound waves. For the amplitude of the gravitational wave spectrum visible today, we find a suppression factor arising from the finite lifetime of the sound waves and compare with the commonly used result in the literature, which corresponds to the asymptotic value of our suppression factor. We point out that the asymptotic value is only applicable for a very long lifetime of the sound waves, which is highly unlikely due to the onset of shocks, turbulence and other damping processes. We also point out that features of the gravitational wave spectral form may hold the tantalizing possibility of distinguishing between different expansion histories using phase transitions.

Subfields: Astronomy and Astrophysics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/14212dfc5613f2c6c5a450bb6b7dc8faeac10ac7

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Daniel G. Figueroa
2. V. Domcke
3. G. White
4. Marco Peloso
5. F. Muia
6. F. Quevedo
7. O. Gould
8. T. Tenkanen

In Statistical and Nonlinear Physics

1. Marco Peloso
2. F. Quevedo
3. A. Ricciardone
4. V. Domcke
5. R. Kallosh
6. A. Uranga

Citations in the corpus

• Theoretical uncertainties for cosmological first-order phase transitions (2020, background): “where Ωmax,min are the maximum and minimum peak of the SGWB spectrum due to sound waves (sw) [1, 94, 147].”
• Challenges and opportunities of gravitational-wave searches at MHz to GHz frequencies (2020, background): “Denoting the lifetime of the velocity perturbations by sv, the peak GW amplitude can be estimated as Hindmarsh et al. (2015); Guo et al. (2021) XGW;0 ’ 3 ðH R Þ 1 1 ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1þ 2H sv p 100 g ðT Þ 1”