# GUT-scale inflation with sizeable tensor modes

## Abstract

A sizeable tensor-to-scalar ratio, such as recently claimed by BICEP2, would imply a scale of inflation at the typical scale of supersymmetric grand unification. This could be an accident, or strong support for supersymmetric theories. Models of F-term hybrid inflation naturally connect the GUT scale with the inflationary scale, but they also predict the tensor-to-scalar ratio to be unmeasurably small. In this work we analyze a general UV embedding of F-term hybrid inflation into a supergravity theory with a general Kähler potential. The CMB observables are generated during the early phase of inflation, at large inflaton values, where the potential is dominated by Planck-suppressed operators. Tuning the leading higher-order terms can give an inflaton potential with sizeable tensor fluctuations and a field excursion which is still sub-Planckian but close to the Planck scale, as expected from the Lyth bound.

- Authors:

- SISSA/INFN, Via Bonomea 265, 34136 Trieste (Italy)
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom)

- Publication Date:

- OSTI Identifier:
- 22373364

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 08; 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; COSMOLOGICAL INFLATION; FLUCTUATIONS; GRAND UNIFIED THEORY; POTENTIALS; SUPERGRAVITY; SUPERSYMMETRY; TENSORS

### Citation Formats

```
Brümmer, Felix, Domcke, Valerie, and Sanz, Verónica, E-mail: fbruemmer@sissa.it, E-mail: vdomcke@sissa.it, E-mail: v.sanz@sussex.ac.uk.
```*GUT-scale inflation with sizeable tensor modes*. United States: N. p., 2014.
Web. doi:10.1088/1475-7516/2014/08/066.

```
Brümmer, Felix, Domcke, Valerie, & Sanz, Verónica, E-mail: fbruemmer@sissa.it, E-mail: vdomcke@sissa.it, E-mail: v.sanz@sussex.ac.uk.
```*GUT-scale inflation with sizeable tensor modes*. United States. doi:10.1088/1475-7516/2014/08/066.

```
Brümmer, Felix, Domcke, Valerie, and Sanz, Verónica, E-mail: fbruemmer@sissa.it, E-mail: vdomcke@sissa.it, E-mail: v.sanz@sussex.ac.uk. Fri .
"GUT-scale inflation with sizeable tensor modes". United States.
doi:10.1088/1475-7516/2014/08/066.
```

```
@article{osti_22373364,
```

title = {GUT-scale inflation with sizeable tensor modes},

author = {Brümmer, Felix and Domcke, Valerie and Sanz, Verónica, E-mail: fbruemmer@sissa.it, E-mail: vdomcke@sissa.it, E-mail: v.sanz@sussex.ac.uk},

abstractNote = {A sizeable tensor-to-scalar ratio, such as recently claimed by BICEP2, would imply a scale of inflation at the typical scale of supersymmetric grand unification. This could be an accident, or strong support for supersymmetric theories. Models of F-term hybrid inflation naturally connect the GUT scale with the inflationary scale, but they also predict the tensor-to-scalar ratio to be unmeasurably small. In this work we analyze a general UV embedding of F-term hybrid inflation into a supergravity theory with a general Kähler potential. The CMB observables are generated during the early phase of inflation, at large inflaton values, where the potential is dominated by Planck-suppressed operators. Tuning the leading higher-order terms can give an inflaton potential with sizeable tensor fluctuations and a field excursion which is still sub-Planckian but close to the Planck scale, as expected from the Lyth bound.},

doi = {10.1088/1475-7516/2014/08/066},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 08,

volume = 2014,

place = {United States},

year = {Fri Aug 01 00:00:00 EDT 2014},

month = {Fri Aug 01 00:00:00 EDT 2014}

}