# Inflation in maximal gauged supergravities

## Abstract

We discuss the dynamics of multiple scalar fields and the possibility of realistic inflation in the maximal gauged supergravity. In this paper, we address this problem in the framework of recently discovered 1-parameter deformation of SO(4,4) and SO(5,3) dyonic gaugings, for which the base point of the scalar manifold corresponds to an unstable de Sitter critical point. In the gauge-field frame where the embedding tensor takes the value in the sum of the 36 and 36’ representations of SL(8), we present a scheme that allows us to derive an analytic expression for the scalar potential. With the help of this formalism, we derive the full potential and gauge coupling functions in analytic forms for the SO(3)×SO(3)-invariant subsectors of SO(4,4) and SO(5,3) gaugings, and argue that there exist no new critical points in addition to those discovered so far. For the SO(4,4) gauging, we also study the behavior of 6-dimensional scalar fields in this sector near the Dall’Agata-Inverso de Sitter critical point at which the negative eigenvalue of the scalar mass square with the largest modulus goes to zero as the deformation parameter s approaches a critical value s{sub c}. We find that when the deformation parameter s is taken sufficientlymore »

- Authors:

- Theory Center, KEK,Tsukuba 305-0801 (Japan)
- (Japan)
- Dipartimento di Fisica, Università di Milano, and INFN, Sezione di Milano,Via Celoria 16, 20133 Milano (Italy)

- Publication Date:

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

- OSTI Identifier:
- 22454548

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 05; Other Information: PUBLISHER-ID: JCAP05(2015)028; OAI: oai:repo.scoap3.org:10334; 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)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGICAL INFLATION; DE SITTER GROUP; EIGENVALUES; GAUGE INVARIANCE; SCALAR FIELDS; SCALARS; SO GROUPS; STRING MODELS; SUPERGRAVITY; SUPERSYMMETRY; TENSORS

### Citation Formats

```
Kodama, Hideo, Department of Particles and Nuclear Physics,The Graduate University for Advanced Studies,Tsukuba 305-0801, and Nozawa, Masato.
```*Inflation in maximal gauged supergravities*. United States: N. p., 2015.
Web. doi:10.1088/1475-7516/2015/05/028.

```
Kodama, Hideo, Department of Particles and Nuclear Physics,The Graduate University for Advanced Studies,Tsukuba 305-0801, & Nozawa, Masato.
```*Inflation in maximal gauged supergravities*. United States. doi:10.1088/1475-7516/2015/05/028.

```
Kodama, Hideo, Department of Particles and Nuclear Physics,The Graduate University for Advanced Studies,Tsukuba 305-0801, and Nozawa, Masato. Mon .
"Inflation in maximal gauged supergravities". United States.
doi:10.1088/1475-7516/2015/05/028.
```

```
@article{osti_22454548,
```

title = {Inflation in maximal gauged supergravities},

author = {Kodama, Hideo and Department of Particles and Nuclear Physics,The Graduate University for Advanced Studies,Tsukuba 305-0801 and Nozawa, Masato},

abstractNote = {We discuss the dynamics of multiple scalar fields and the possibility of realistic inflation in the maximal gauged supergravity. In this paper, we address this problem in the framework of recently discovered 1-parameter deformation of SO(4,4) and SO(5,3) dyonic gaugings, for which the base point of the scalar manifold corresponds to an unstable de Sitter critical point. In the gauge-field frame where the embedding tensor takes the value in the sum of the 36 and 36’ representations of SL(8), we present a scheme that allows us to derive an analytic expression for the scalar potential. With the help of this formalism, we derive the full potential and gauge coupling functions in analytic forms for the SO(3)×SO(3)-invariant subsectors of SO(4,4) and SO(5,3) gaugings, and argue that there exist no new critical points in addition to those discovered so far. For the SO(4,4) gauging, we also study the behavior of 6-dimensional scalar fields in this sector near the Dall’Agata-Inverso de Sitter critical point at which the negative eigenvalue of the scalar mass square with the largest modulus goes to zero as the deformation parameter s approaches a critical value s{sub c}. We find that when the deformation parameter s is taken sufficiently close to the critical value, inflation lasts more than 60 e-folds even if the initial point of the inflaton allows an O(0.1) deviation in Planck units from the Dall’Agata-Inverso critical point. It turns out that the spectral index n{sub s} of the curvature perturbation at the time of the 60 e-folding number is always about 0.96 and within the 1σ range n{sub s}=0.9639±0.0047 obtained by Planck, irrespective of the value of the η parameter at the critical saddle point. The tensor-scalar ratio predicted by this model is around 10{sup −3} and is close to the value in the Starobinsky model.},

doi = {10.1088/1475-7516/2015/05/028},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 05,

volume = 2015,

place = {United States},

year = {Mon May 18 00:00:00 EDT 2015},

month = {Mon May 18 00:00:00 EDT 2015}

}