# Gravity waves from non-minimal quadratic inflation

## Abstract

We discuss non-minimal quadratic inflation in supersymmetric (SUSY) and non-SUSY models which entails a linear coupling of the inflaton to gravity. Imposing a lower bound on the parameter c{sub R}, involved in the coupling between the inflaton and the Ricci scalar curvature, inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity up to the Planck scale. Working in the non-SUSY context we also consider radiative corrections to the inflationary potential due to a possible coupling of the inflaton to bosons or fermions. We find ranges of the parameters, depending mildly on the renormalization scale, with adjustable values of the spectral index n{sub s}, tensor-to-scalar ratio r≅(2−4)⋅ 10{sup −3}, and an inflaton mass close to 3⋅ 10{sup 13} GeV. In the SUSY framework we employ two gauge singlet chiral superfields, a logarithmic Kähler potential including all the allowed terms up to fourth order in powers of the various fields, and determine uniquely the superpotential by applying a continuous R and a global U(1) symmetry. When the Kähler manifold exhibits a no-scale-type symmetry, the model predicts n{sub s} ≅ 0.963 and r≅ 0.004. Beyond no-scale SUGRA, n{sub s} and r depend crucially on the coefficient involvedmore »

- Authors:

- Departament de Física Teòrica and IFIC, Universitat de València-CSIC, E-46100 Burjassot (Spain)
- Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

- Publication Date:

- OSTI Identifier:
- 22524859

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 03; Other Information: Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BOSONS; CHIRALITY; COSMOLOGICAL INFLATION; COUPLING; FERMIONS; GEV RANGE; GRAVITATION; GRAVITY WAVES; INFLATONS; MASS; POTENTIALS; RADIATIVE CORRECTIONS; RENORMALIZATION; SCALARS; SUPERSYMMETRY; TENSORS; U-1 GROUPS; UNITARITY

### Citation Formats

```
Pallis, Constantinos, and Shafi, Qaisar, E-mail: cpallis@ific.uv.es, E-mail: shafi@bartol.udel.edu.
```*Gravity waves from non-minimal quadratic inflation*. United States: N. p., 2015.
Web. doi:10.1088/1475-7516/2015/03/023.

```
Pallis, Constantinos, & Shafi, Qaisar, E-mail: cpallis@ific.uv.es, E-mail: shafi@bartol.udel.edu.
```*Gravity waves from non-minimal quadratic inflation*. United States. doi:10.1088/1475-7516/2015/03/023.

```
Pallis, Constantinos, and Shafi, Qaisar, E-mail: cpallis@ific.uv.es, E-mail: shafi@bartol.udel.edu. Sun .
"Gravity waves from non-minimal quadratic inflation". United States.
doi:10.1088/1475-7516/2015/03/023.
```

```
@article{osti_22524859,
```

title = {Gravity waves from non-minimal quadratic inflation},

author = {Pallis, Constantinos and Shafi, Qaisar, E-mail: cpallis@ific.uv.es, E-mail: shafi@bartol.udel.edu},

abstractNote = {We discuss non-minimal quadratic inflation in supersymmetric (SUSY) and non-SUSY models which entails a linear coupling of the inflaton to gravity. Imposing a lower bound on the parameter c{sub R}, involved in the coupling between the inflaton and the Ricci scalar curvature, inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity up to the Planck scale. Working in the non-SUSY context we also consider radiative corrections to the inflationary potential due to a possible coupling of the inflaton to bosons or fermions. We find ranges of the parameters, depending mildly on the renormalization scale, with adjustable values of the spectral index n{sub s}, tensor-to-scalar ratio r≅(2−4)⋅ 10{sup −3}, and an inflaton mass close to 3⋅ 10{sup 13} GeV. In the SUSY framework we employ two gauge singlet chiral superfields, a logarithmic Kähler potential including all the allowed terms up to fourth order in powers of the various fields, and determine uniquely the superpotential by applying a continuous R and a global U(1) symmetry. When the Kähler manifold exhibits a no-scale-type symmetry, the model predicts n{sub s} ≅ 0.963 and r≅ 0.004. Beyond no-scale SUGRA, n{sub s} and r depend crucially on the coefficient involved in the fourth order term, which mixes the inflaton with the accompanying non-inflaton field in the Kähler potential, and the prefactor encountered in it. Increasing slightly the latter above (−3), an efficient enhancement of the resulting r can be achieved putting it in the observable range. The inflaton mass in the last case is confined in the range (5−9)⋅ 10{sup 13} GeV.},

doi = {10.1088/1475-7516/2015/03/023},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 03,

volume = 2015,

place = {United States},

year = {Sun Mar 01 00:00:00 EST 2015},

month = {Sun Mar 01 00:00:00 EST 2015}

}