How thermal inflation can save minimal hybrid inflation in supergravity
Abstract
Minimal hybrid inflation in supergravity has been ruled out by the 2015 Planck observations because the spectral index of the produced curvature perturbation falls outside observational bounds. To resurrect the model, a number of modifications have been put forward but many of them spoil the accidental cancellation that resolves the ηproblem and require complicated Kähler constructions to counterbalance the lost cancellation. In contrast, in this paper the model is rendered viable by supplementing the scenario with a brief period of thermal inflation, which follows the reheating of primordial inflation. The scalar field responsible for thermal inflation requires a large nonzero vacuum expectation value (VEV) and a flat potential. We investigate the VEV of such a flaton field and its subsequent effect on the inflationary observables. We find that, for large VEV, minimal hybrid inflation in supergravity produces a spectral index within the 1σ Planck bound and a tensortoscalar ratio which may be observable in the near future. The mechanism is applicable to other inflationary models.
 Authors:

 Consortium for Fundamental Physics, Physics Department,Lancaster University, Lancaster LA1 4YB (United Kingdom)
 Publication Date:
 Sponsoring Org.:
 SCOAP3, CERN, Geneva (Switzerland)
 OSTI Identifier:
 22572164
 Resource Type:
 Journal Article
 Journal Name:
 Journal of Cosmology and Astroparticle Physics
 Additional Journal Information:
 Journal Volume: 2016; Journal Issue: 10; Other Information: PUBLISHERID: JCAP10(2016)020; OAI: oai:repo.scoap3.org:17557; ccby Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 14757516
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGICAL INFLATION; EXPECTATION VALUE; INFLATIONARY UNIVERSE; INFLATONS; SCALAR FIELDS; SUPERGRAVITY; UNIVERSE; VACUUM STATES
Citation Formats
Dimopoulos, Konstantinos, and Owen, Charlotte. How thermal inflation can save minimal hybrid inflation in supergravity. United States: N. p., 2016.
Web. doi:10.1088/14757516/2016/10/020.
Dimopoulos, Konstantinos, & Owen, Charlotte. How thermal inflation can save minimal hybrid inflation in supergravity. United States. doi:10.1088/14757516/2016/10/020.
Dimopoulos, Konstantinos, and Owen, Charlotte. Wed .
"How thermal inflation can save minimal hybrid inflation in supergravity". United States. doi:10.1088/14757516/2016/10/020.
@article{osti_22572164,
title = {How thermal inflation can save minimal hybrid inflation in supergravity},
author = {Dimopoulos, Konstantinos and Owen, Charlotte},
abstractNote = {Minimal hybrid inflation in supergravity has been ruled out by the 2015 Planck observations because the spectral index of the produced curvature perturbation falls outside observational bounds. To resurrect the model, a number of modifications have been put forward but many of them spoil the accidental cancellation that resolves the ηproblem and require complicated Kähler constructions to counterbalance the lost cancellation. In contrast, in this paper the model is rendered viable by supplementing the scenario with a brief period of thermal inflation, which follows the reheating of primordial inflation. The scalar field responsible for thermal inflation requires a large nonzero vacuum expectation value (VEV) and a flat potential. We investigate the VEV of such a flaton field and its subsequent effect on the inflationary observables. We find that, for large VEV, minimal hybrid inflation in supergravity produces a spectral index within the 1σ Planck bound and a tensortoscalar ratio which may be observable in the near future. The mechanism is applicable to other inflationary models.},
doi = {10.1088/14757516/2016/10/020},
journal = {Journal of Cosmology and Astroparticle Physics},
issn = {14757516},
number = 10,
volume = 2016,
place = {United States},
year = {2016},
month = {10}
}