Moduli vacuum misalignment and precise predictions in string inflation
Abstract
The predictions for all the cosmological observables of any inflationary model depend on the number of efoldings which is sensitive to the postinflationary history of the universe. In string models the generic presence of light moduli leads to a latetime period of matter domination which lowers the required number of efoldings and, in turn, modifies the exact predictions of any inflationary model. In this paper we compute exactly the shift of the number of efoldings in Kähler moduli inflation which is determined by the magnitude of the moduli initial displacement caused by vacuum misalignment and the moduli decay rates. We find that the preferred number of efoldings gets reduced from 50 to 45, causing a modification of the spectral index at the percent level. Our results illustrate the importance of understanding the full postinflationary evolution of the universe in order to derive precise predictions in string inflation. To perform this task it is crucial to work in a setting where there is good control over moduli stabilisation.
 Authors:

 Dipartimento di Fisica ed Astronomia, Università di Bologna,via Irnerio 46, 40126 Bologna (Italy)
 Theory Division, Saha Institute of Nuclear Physics,1/AF Salt Lake, Kolkata 700064 (India)
 Harish Chandra Research Intitute,Chattnag Road, Jhunsi, Allahabad 211019 (India)
 Abdus Salam ICTP,Strada Costiera 11, Trieste 34014 (Italy)
 Publication Date:
 Sponsoring Org.:
 SCOAP3, CERN, Geneva (Switzerland)
 OSTI Identifier:
 22572127
 Resource Type:
 Journal Article
 Journal Name:
 Journal of Cosmology and Astroparticle Physics
 Additional Journal Information:
 Journal Volume: 2016; Journal Issue: 08; Other Information: PUBLISHERID: JCAP08(2016)006; OAI: oai:repo.scoap3.org:16675; 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; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COSMOLOGICAL INFLATION; COSMOLOGY; INFLATIONARY UNIVERSE; MATHEMATICAL EVOLUTION; STRING MODELS; STRING THEORY; UNIVERSE
Citation Formats
Cicoli, Michele, INFN sezione di Bologna,viale Berti Pichat 6/2, 40127 Bologna, Abdus Salam ICTP,Strada Costiera 11, Trieste 34014, Dutta, Koushik, Maharana, Anshuman, Quevedo, Fernando, and DAMTP, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA. Moduli vacuum misalignment and precise predictions in string inflation. United States: N. p., 2016.
Web. doi:10.1088/14757516/2016/08/006.
Cicoli, Michele, INFN sezione di Bologna,viale Berti Pichat 6/2, 40127 Bologna, Abdus Salam ICTP,Strada Costiera 11, Trieste 34014, Dutta, Koushik, Maharana, Anshuman, Quevedo, Fernando, & DAMTP, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA. Moduli vacuum misalignment and precise predictions in string inflation. United States. doi:10.1088/14757516/2016/08/006.
Cicoli, Michele, INFN sezione di Bologna,viale Berti Pichat 6/2, 40127 Bologna, Abdus Salam ICTP,Strada Costiera 11, Trieste 34014, Dutta, Koushik, Maharana, Anshuman, Quevedo, Fernando, and DAMTP, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA. Wed .
"Moduli vacuum misalignment and precise predictions in string inflation". United States. doi:10.1088/14757516/2016/08/006.
@article{osti_22572127,
title = {Moduli vacuum misalignment and precise predictions in string inflation},
author = {Cicoli, Michele and INFN sezione di Bologna,viale Berti Pichat 6/2, 40127 Bologna and Abdus Salam ICTP,Strada Costiera 11, Trieste 34014 and Dutta, Koushik and Maharana, Anshuman and Quevedo, Fernando and DAMTP, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA},
abstractNote = {The predictions for all the cosmological observables of any inflationary model depend on the number of efoldings which is sensitive to the postinflationary history of the universe. In string models the generic presence of light moduli leads to a latetime period of matter domination which lowers the required number of efoldings and, in turn, modifies the exact predictions of any inflationary model. In this paper we compute exactly the shift of the number of efoldings in Kähler moduli inflation which is determined by the magnitude of the moduli initial displacement caused by vacuum misalignment and the moduli decay rates. We find that the preferred number of efoldings gets reduced from 50 to 45, causing a modification of the spectral index at the percent level. Our results illustrate the importance of understanding the full postinflationary evolution of the universe in order to derive precise predictions in string inflation. To perform this task it is crucial to work in a setting where there is good control over moduli stabilisation.},
doi = {10.1088/14757516/2016/08/006},
journal = {Journal of Cosmology and Astroparticle Physics},
issn = {14757516},
number = 08,
volume = 2016,
place = {United States},
year = {2016},
month = {8}
}