Large Density Perturbations from Reheating to Standard Model particles due to the Dynamics of the Higgs Boson during Inflation

Abstract

Cosmic Microwave Background (CMB) observations are used to constrain reheating to Standard Model (SM) particles after a period of inflation. As a light spectator field, the SM Higgs boson acquires large field values from its quantum fluctuations during inflation, gives masses to SM particles that vary from one Hubble patch to another, and thereby produces large density fluctuations. We consider both perturbative and resonant decay of the inflaton to SM particles. For the case of perturbative decay from coherent oscillations of the inflaton after high scale inflation, we find strong constraints on the reheat temperature for the inflaton decay into heavy SM particles. For the case of resonant particle production (preheating) to (Higgsed) SM gauge bosons, we find temperature fluctuations larger than observed in the CMB for a range of gauge coupling that includes those found in the SM and conclude that such preheating cannot be the main source of reheating the Universe after inflation.

Primordial non-Gaussianity from the Effects of the Standard Model Higgs during Reheating after Inflation

“…We find that CMB bounds on NG set by the Planck measurements [31] provide even more powerful constraints than those obtained in Ref. [30] and, thus, exclude the possibility of perturbations from Higgs-modulated reheating providing the dominant contribution to the observed power spectrum of temperature anisotropies. By connecting primordial NG to SM parameters such as the Higgs self-coupling, we demonstrate that future NG signals can be used to probe the evolution of the Higgs field during inflation, thereby probing its potential over energies that are otherwise inaccessible.…”

“…In Ref. [30], we show that the results for the temperature fluctuation amplitude are nearly identical by assuming either slow or rapid Higgs oscillations. We have verified that taking either limit for Higgs oscillations yields similar results for the NG and only present one case for clarity.…”

“…In Ref. [30] we computed the amplitude of Higgsinduced temperature anisotropies and used CMB data to constrain model parameters. In this work, we show that the non-linearity of Higgs-modulated reheating processes can be the cause of significant NG in the resulting density perturbation spectrum.…”

“…The gauge-invariant Bardeen parameter [36] produced by Higgs effects in each patch, ζ i H , is obtained by solving [11,30]…”

Higgs-like spectator field as the origin of structure

“…[8] for the general formalism of modulated reheating, and to Refs. [9][10][11][12][13][14][15][16][17] for models with a specific focus on the Higgs field. Further related work can be found in Refs.…”