# Calculations of inflaton decays and reheating: with applications to no-scale inflation models

## Abstract

We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, w, during the epoch of inflaton decay, the reheating temperature, T{sub reh}, and the number of inflationary e-folds, N{sub ∗}, comparing analytical approximations with numerical calculations. We then illustrate these results with applications to models based on no-scale supergravity and motivated by generic string compactifications, including scenarios where the inflaton is identified as an untwisted-sector matter field with direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions. Finally, we use our results to discuss the constraints on these models imposed by present measurements of the scalar spectral index n{sub s} and the tensor-to-scalar perturbation ratio r, converting them into constraints on N{sub ∗}, the inflaton decay rate and other parameters of specific no-scale inflationary models.

- Authors:

- Theoretical Particle Physics and Cosmology Group, Department of Physics,King’s College London,London WC2R 2LS (United Kingdom)
- (Switzerland)
- William I. Fine Theoretical Physics Institute, School of Physics and Astronomy,University of Minnesota,116 Church Street SE, Minneapolis, MN 55455 (United States)
- George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University,College Station, 77843 Texas (United States)
- (HARC), Mitchell Campus, Woodlands, 77381 Texas (United States)
- (Greece)

- Publication Date:

- Sponsoring Org.:
- SCOAP3, CERN, Geneva (Switzerland)

- OSTI Identifier:
- 22458357

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Cosmology and Astroparticle Physics

- Additional Journal Information:
- Journal Volume: 2015; Journal Issue: 07; Other Information: PUBLISHER-ID: JCAP07(2015)050; OAI: oai:repo.scoap3.org:11290; 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 1475-7516

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGICAL INFLATION; COSMOLOGY; EQUATIONS OF STATE; LIMITING VALUES; PERTURBATION THEORY; SUPERGRAVITY; SUPERSYMMETRY

### Citation Formats

```
Ellis, John, Theory Division, CERN,CH-1211 Geneva 23, Garcia, Marcos A.G., Nanopoulos, Dimitri V., Astroparticle Physics Group, Houston Advanced Research Center, Academy of Athens, Division of Natural Sciences,28 Panepistimiou Avenue, Athens 10679, and Olive, Keith A.
```*Calculations of inflaton decays and reheating: with applications to no-scale inflation models*. United States: N. p., 2015.
Web. doi:10.1088/1475-7516/2015/07/050.

```
Ellis, John, Theory Division, CERN,CH-1211 Geneva 23, Garcia, Marcos A.G., Nanopoulos, Dimitri V., Astroparticle Physics Group, Houston Advanced Research Center, Academy of Athens, Division of Natural Sciences,28 Panepistimiou Avenue, Athens 10679, & Olive, Keith A.
```*Calculations of inflaton decays and reheating: with applications to no-scale inflation models*. United States. doi:10.1088/1475-7516/2015/07/050.

```
Ellis, John, Theory Division, CERN,CH-1211 Geneva 23, Garcia, Marcos A.G., Nanopoulos, Dimitri V., Astroparticle Physics Group, Houston Advanced Research Center, Academy of Athens, Division of Natural Sciences,28 Panepistimiou Avenue, Athens 10679, and Olive, Keith A. Thu .
"Calculations of inflaton decays and reheating: with applications to no-scale inflation models". United States. doi:10.1088/1475-7516/2015/07/050.
```

```
@article{osti_22458357,
```

title = {Calculations of inflaton decays and reheating: with applications to no-scale inflation models},

author = {Ellis, John and Theory Division, CERN,CH-1211 Geneva 23 and Garcia, Marcos A.G. and Nanopoulos, Dimitri V. and Astroparticle Physics Group, Houston Advanced Research Center and Academy of Athens, Division of Natural Sciences,28 Panepistimiou Avenue, Athens 10679 and Olive, Keith A.},

abstractNote = {We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, w, during the epoch of inflaton decay, the reheating temperature, T{sub reh}, and the number of inflationary e-folds, N{sub ∗}, comparing analytical approximations with numerical calculations. We then illustrate these results with applications to models based on no-scale supergravity and motivated by generic string compactifications, including scenarios where the inflaton is identified as an untwisted-sector matter field with direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions. Finally, we use our results to discuss the constraints on these models imposed by present measurements of the scalar spectral index n{sub s} and the tensor-to-scalar perturbation ratio r, converting them into constraints on N{sub ∗}, the inflaton decay rate and other parameters of specific no-scale inflationary models.},

doi = {10.1088/1475-7516/2015/07/050},

journal = {Journal of Cosmology and Astroparticle Physics},

issn = {1475-7516},

number = 07,

volume = 2015,

place = {United States},

year = {2015},

month = {7}

}