Gravitational waves and black holes from the phase transition in models of dynamical symmetry breaking

TL;DR

This paper investigates the cosmological signals, including gravitational waves and primordial black holes, resulting from strong first order phase transitions in models of dynamical electroweak symmetry breaking, highlighting potential observability in future experiments.

Contribution

It provides detailed predictions of gravitational wave signals and black hole formation in specific dynamical symmetry breaking models, including the role of additional scalar or gauge particles.

Findings

Gravitational waves from these phase transitions are detectable in future experiments.

Primordial black holes can form but are often overshadowed by dark matter contributions.

Models with stable extra particles can produce dark matter candidates.

Abstract

Theories of dynamical electroweak symmetry breaking predict a strong first order cosmological phase transition: we compute the resulting signals, primordial black holes and gravitational waves. These theories employ one SM-neutral scalar, plus some extra model-dependent particle to get the desired quantum potential out of classical scale invariance. We consider models where the extra particle is a scalar singlet, or vectors of an extended U(1) or SU(2) gauge sector. In models where the extra particle is stable, it provides a particle Dark Matter candidate with freeze-out abundance that tends to dominate over primordial black holes. These can instead be DM in models without a particle DM candidate. Gravitational waves arise at a level observable in future searches, even in regions where DM cannot be directly tested.