Higgscitement: Cosmological Dynamics of Fine Tuning

TL;DR

This paper explores how the fine-tuning of the Higgs potential can induce a new early universe epoch with violent Higgs-modulus dynamics, leading to gravitational waves and affecting inflationary model fits.

Contribution

It introduces a novel cosmological scenario where Higgs fine-tuning causes violent early universe dynamics and gravitational wave production, with implications for inflation.

Findings

Higgs-modulus coupling can trigger tachyonic Higgs production

Violent dynamics lead to gravitational wave signals

Nonlinear effects influence the inflation-to-CMB timeline

Abstract

The Higgs potential appears to be fine-tuned, hence very sensitive to values of other scalar fields that couple to the Higgs. We show that this feature can lead to a new epoch in the early universe featuring violent dynamics coupling the Higgs to a scalar modulus. The oscillating modulus drives tachyonic Higgs particle production. We find a simple parametric understanding of when this process can lead to rapid modulus fragmentation, resulting in gravitational wave production. A nontrivial equation-of-state arising from the nonlinear dynamics also affects the time elapsed from inflation to the CMB, influencing fits of inflationary models. Supersymmetric theories automatically contain useful ingredients for this picture.