Title: Is a Higgs vacuum instability fatal for high-scale inflation?

Abstract

We study the inflationary evolution of a scalar field h with an unstable potential for the case where the Hubble parameter H during inflation is larger than the instability scale Λ_I of the potential. Quantum fluctuations in the field of size δh ~ H/2π imply that the unstable part of the potential is sampled during inflation. We investigate the evolution of these fluctuations to the unstable regime and in particular whether they generate cosmological defects or even terminate inflation. We apply the results of a toy scalar model to the case of the Standard Model (SM) Higgs boson, the quartic of which evolves to negative values at high scales, and extend previous analyses of Higgs dynamics during inflation utilizing statistical methods to a perturbative and fully gauge-invariant formulation. We show that the dynamics are controlled by the renormalization group-improved quartic coupling λ(μ) evaluated at a scale μ = H, such that Higgs fluctuations are enhanced by the instability if H > Λ_I. Even if H > Λ_I, the instability in the Standard Model Higgs potential does not end inflation; instead the universe slowly sloughs off crunching patches of space that never come to dominate the evolution. As inflation proceeds pastmore » 50 e-folds, a significant proportion of patches exits inflation in the unstable vacuum, and as much as 1% of the spacetime can rapidly evolve to a defect. Depending on the nature of these defects, however, the resulting universe could still be compatible with ours.« less

Authors:

Kearney, John ^[1]; Yoo, Hojin ^[2]; Zurek, Kathryn M. ^[2]

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+ Show Author Affiliations

1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)

Publication Date:

Thu Jun 25 00:00:00 EDT 2015

Research Org.:

Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), High Energy Physics (HEP)

OSTI Identifier:

1226319

Alternate Identifier(s):

OSTI ID: 1198521

Report Number(s):

FERMILAB-PUB-15-090-T
Journal ID: ISSN 1550-7998; PRVDAQ; arXiv eprint number arXiv:1503.05193

Grant/Contract Number:  

AC02-07CH11359; AC02-05CH11231; SC0007859

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review. D, Particles, Fields, Gravitation and Cosmology

Additional Journal Information:

Journal Volume: 91; Journal Issue: 12; Journal ID: ISSN 1550-7998

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS