Gravitational waves from a very strong electroweak phase transition

LEONARDO LEITAO; ARIEL MÉGEVAND

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2016 vol. 2016 p. 37 - 66

1475-7516

We investigate the production of a stochastic background of gravitational wavesin the electroweak phase transition. We consider extensions of the StandardModel which can give very strongly first-order phase transitions, such that thetransition fronts either propagate as detonations or run away. To compute thebubble wall velocity, we estimate the friction with the plasma and take intoaccount the hydrodynamics. We track the development of the phase transition upto the percolation time, and we calculate the gravitational wave spectrumgenerated by bubble collisions, magnetohydrodynamic turbulence, and soundwaves. For the kinds of models we consider, we find parameter regions for whichthe gravitational waves are potentially observable at the planned space-basedinterferometer eLISA. In such cases, the signal from sound waves is generallydominant, while that from bubble collisions is the least significant of them.Since the sound waves and turbulence mechanisms are diminished for runawaywalls, the models with the best prospects of detection at eLISA are those whichdo not have such solutions. In particular, we find that heavy extra bosonsprovide stronger gravitational wave signals than tree-level terms.