Gravitational freeze-in dark matter from Higgs Preheating

TL;DR

This paper investigates gravitational freeze-in dark matter production during Higgs preheating, revealing a new parameter space where dark matter mass exceeds inflaton mass, using lattice simulations to analyze non-perturbative resonance effects.

Contribution

It introduces a detailed lattice simulation study of gravitational freeze-in during Higgs preheating, identifying viable resonance conditions and a novel dark matter mass parameter space.

Findings

Tachyonic resonance is suppressed by Higgs self-interaction back reaction.

Parameter resonance is achievable with small Higgs self-coupling.

A new dark matter parameter space with mass larger than inflaton mass is uncovered.

Abstract

Gravitational freeze-in is a mechanism to explain the observed dark matter relic density if dark matter neither couples to inflation nor to standard model sector. In this work, we study gravitational freeze-in dark matter production during Higgs preheating based on non-perturbative resonance. Using reliable lattice method to handle this non-perturbative process, we show that tachyonic resonance is prohibited by strong back reaction due to Higgs self interaction needed to keep the positivity of potential during preheating, and parameter resonance is viable by tuning the Higgs self-interaction coupling to be small enough in ultraviolet energy scale. We then derive the dark matter relic density under the context of Higgs preheating, and uncover a new dark matter parameter space with dark matter mass larger than inflaton mass, which arises from out-of-equilium Higgs annihilation. Finally, we briefly remark the open question of testing gravitational dark matter.