Thermal perturbations from cosmological constant relaxation
| Autor: | Lingyuan Ji, David E. Kaplan, Surjeet Rajendran, Erwin H. Tanin |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
High Energy Physics - Theory
Cosmology and Nongalactic Astrophysics (astro-ph.CO) 010308 nuclear & particles physics FOS: Physical sciences General Relativity and Quantum Cosmology (gr-qc) Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences General Relativity and Quantum Cosmology High Energy Physics - Phenomenology High Energy Physics - Phenomenology (hep-ph) High Energy Physics - Theory (hep-th) 0103 physical sciences 010306 general physics Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Physical Review |
| ISSN: | 2470-0029 2470-0010 |
| Popis: | We probe the cosmological consequences of a recently proposed class of solutions to the cosmological constant problem. In these models, the universe undergoes a long period of inflation followed by a contraction and a bounce that sets the stage for the hot big bang era. A requirement of any successful early universe model is that it must reproduce the observed scale-invariant density perturbations at cosmic microwave background (CMB) scales. While these class of models involve a long period of inflation, the inflationary Hubble scale during their observationally relevant stages is at or below the current Hubble scale, rendering the de Sitter fluctuations too weak to seed the CMB anisotropies. We show that sufficiently strong perturbations can still be sourced thermally if the relaxion field serving as the inflaton interacts with a thermal bath, which can be generated and maintained by the same interaction. We present a simple model where the relaxion field is derivatively (i.e., technically naturally) coupled to a non-Abelian gauge sector, which gets excited tachyonically and subsequently thermalizes due to its nonlinear self-interactions. This model explains both the smallness of the cosmological constant and the amplitude of CMB anisotropies. |
| Databáze: | OpenAIRE |
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