Bubble wall velocity: heavy physics effects

TL;DR

This paper investigates how heavy physics effects influence the velocity of bubble walls during first order phase transitions, especially at ultra-relativistic speeds, revealing significant modifications to bubble dynamics and phenomenology.

Contribution

It introduces the impact of heavy fields on bubble wall friction and explores next-to-leading order effects from soft vector emissions, advancing understanding of bubble expansion dynamics.

Findings

Heavy fields can significantly alter bubble wall velocity.

NLO effects from soft vector emissions are relevant.

Heavy physics effects modify phenomenological outcomes.

Abstract

We analyse the dynamics of the relativistic bubble expansion during the first order phase transition focusing on the ultra relativistic velocities $\gamma\gg 1$. We show that fields much heavier than the scale of the phase transition can significantly contribute to the friction and modify the motion of the bubble wall leading to interesting phenomenological consequences. NLO effects on the friction due to the soft vector field emission are reviewed as well.