Cosmological implications of the Higgs mass measurement

TL;DR

This paper explores how the measured Higgs mass impacts early Universe cosmology, including stability, reheat temperature bounds, and the likelihood of observed perturbations within inflation models, assuming the Standard Model's validity at high energies.

Contribution

It provides new bounds on reheat temperature based on Higgs stability and analyzes the probability of matching cosmological observations with a light Higgs within inflation scenarios.

Findings

Higgs potential instability occurs for Mh < 130 GeV.

Reheat temperature is constrained by Higgs stability considerations.

Light Higgs makes it highly improbable to produce observed cosmological perturbations in large-field inflation models.

Abstract

We assume the validity of the Standard Model up to an arbitrary high-energy scale and discuss what information on the early stages of the Universe can be extracted from a measurement of the Higgs mass. For Mh < 130 GeV, the Higgs potential can develop an instability at large field values. From the absence of excessive thermal Higgs field fluctuations we derive a bound on the reheat temperature after inflation as a function of the Higgs and top masses. Then we discuss the interplay between the quantum Higgs fluctuations generated during the primordial stage of inflation and the cosmological perturbations, in the context of landscape scenarios in which the inflationary parameters scan. We show that, within the large-field models of inflation, it is highly improbable to obtain the observed cosmological perturbations in a Universe with a light Higgs. Moreover, independently of the inflationary model, the detection of primordial tensor perturbations through the B-mode of CMB polarization and the discovery of a light Higgs can simultaneously occur only with exponentially small probability, unless there is new physics beyond the Standard Model.