# Primordial fluctuations from inflation in dRGT bimetric theory of gravity

## Abstract

We investigate primordial gravitational waves and curvature perturbations in de Rham-Gabadadze-Tolley (dRGT) bimetric gravity. We evaluate the power-spectra in the leading order in slow roll. Taking into account the decay of massive graviton, we find that the action up to the second order reduces to the Einstein theory with a non-minimally coupled scalar field, which is simplified to a minimally coupled model by conformal transformation. We also find that the tensor to scalar ratio for large field inflation with power law potential is larger than the general relativity counterpart for any choice of parameters in dRGT bimetric gravity. In addition, we confirm that the usual consistency relation holds and we have a steeper spectrum for gravitational waves.

- Authors:

- Department of Physics, Kyoto University,Kyoto 606-8502 (Japan)
- (RESCEU), Graduate School of Science,The University of Tokyo, Tokyo 113-0033 (Japan)
- (Japan)

- Publication Date:

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

- OSTI Identifier:
- 22572153

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2016; Journal Issue: 09; Other Information: PUBLISHER-ID: JCAP09(2016)033; OAI: oai:repo.scoap3.org:17223; cc-by 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:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACTION INTEGRAL; CONFORMAL INVARIANCE; COSMOLOGICAL INFLATION; GENERAL RELATIVITY THEORY; GRAVITATIONAL WAVES; INFLATIONARY UNIVERSE; METRICS; PERTURBATION THEORY; SCALAR FIELDS

### Citation Formats

```
Sakakihara, Yuki, Research Center for the Early Universe, Tanaka, Takahiro, and Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502.
```*Primordial fluctuations from inflation in dRGT bimetric theory of gravity*. United States: N. p., 2016.
Web. doi:10.1088/1475-7516/2016/09/033.

```
Sakakihara, Yuki, Research Center for the Early Universe, Tanaka, Takahiro, & Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502.
```*Primordial fluctuations from inflation in dRGT bimetric theory of gravity*. United States. doi:10.1088/1475-7516/2016/09/033.

```
Sakakihara, Yuki, Research Center for the Early Universe, Tanaka, Takahiro, and Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502. Mon .
"Primordial fluctuations from inflation in dRGT bimetric theory of gravity". United States.
doi:10.1088/1475-7516/2016/09/033.
```

```
@article{osti_22572153,
```

title = {Primordial fluctuations from inflation in dRGT bimetric theory of gravity},

author = {Sakakihara, Yuki and Research Center for the Early Universe and Tanaka, Takahiro and Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502},

abstractNote = {We investigate primordial gravitational waves and curvature perturbations in de Rham-Gabadadze-Tolley (dRGT) bimetric gravity. We evaluate the power-spectra in the leading order in slow roll. Taking into account the decay of massive graviton, we find that the action up to the second order reduces to the Einstein theory with a non-minimally coupled scalar field, which is simplified to a minimally coupled model by conformal transformation. We also find that the tensor to scalar ratio for large field inflation with power law potential is larger than the general relativity counterpart for any choice of parameters in dRGT bimetric gravity. In addition, we confirm that the usual consistency relation holds and we have a steeper spectrum for gravitational waves.},

doi = {10.1088/1475-7516/2016/09/033},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 09,

volume = 2016,

place = {United States},

year = {Mon Sep 19 00:00:00 EDT 2016},

month = {Mon Sep 19 00:00:00 EDT 2016}

}