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Related papers: Primordial Gravitational Waves in Bimetric Gravity

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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…

High Energy Physics - Theory · Physics 2016-10-17 Yuki Sakakihara , Takahiro Tanaka

In this paper we study the generation of primordial perturbations in a cosmological setting of bigravity during inflation. We consider a model of bigravity which can reproduce the $\Lambda$CDM background and large scale structure and a…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-02 Giulia Cusin , Ruth Durrer , Pietro Guarato , Mariele Motta

Supersolid inflation is a class of inflationary theories that simultaneously breaks time and space reparameterization invariance during inflation, with distinctive features for the dynamics of cosmological fluctuations. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Angelo Ricciardone , Gianmassimo Tasinato

We study slow-roll inflation and the generation of primordial fluctuations in $F(T)$ gravity's rainbow. We obtain the second order action for scalar and tensor perturbations and then calculate the primordial power spectrum for them. Thus,…

General Relativity and Quantum Cosmology · Physics 2022-02-18 Yoelsy Leyva , Carlos Leiva , Giovanni Otalora , Joel Saavedra

We investigate the inhomogeneous inflation, in which the space exponentially expands with inhomogeneities, and its cosmological perturbations. The inhomogeneous inflation is realized by introducing scalar fields with spacelike gradients…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-11 Xian Gao , Chao Kang

We study the primordial bispectrum of curvature perturbation in the uniform- density slicing generated by the interaction between the inflaton and isotropic background gauge fields. We derive the action up to cubic order in perturbation and…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-05 Hiroyuki Funakoshi , Kei Yamamoto

The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-30 Shyam Balaji , Guillem Domenech , Joseph Silk

In a recent paper [17], we studied the evolution of the background geometry and scalar perturbations in an inflationary, spatially closed Friedmann-Lema\^itre-Robertson-Walker (FLRW) model having constant positive spatial curvature and…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-24 Béatrice Bonga , Brajesh Gupt , Nelson Yokomizo

We reconsider the enhancement of primordial gravitational waves that arises from a quantum gravitational model of inflation. A distinctive feature of this model is that the end of inflation witnesses a brief phase during which the Hubble…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Maria G. Romania , N. C. Tsamis , R. P. Woodard

We study primordial gravitational waves from inflation in Randall-Sundrum braneworld model. The effect of small change of the Hubble parameter during inflation is investigated using a toy model given by connecting two de Sitter branes. We…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Tsutomu Kobayashi , Hideaki Kudoh , Takahiro Tanaka

In warm inflation, dissipation due to the interactions of the inflaton field to other light degrees of freedom leads naturally to the enhancement of the primordial spectrum during the last 10-20 efolds of inflation. We study this effect in…

High Energy Physics - Phenomenology · Physics 2022-01-05 Mar Bastero-Gil , Marta Subías Díaz-Blanco

We investigate constraints on power spectra of the primordial curvature and tensor perturbations with priors based on single-field slow-roll inflation models. We stochastically draw the Hubble slow-roll parameters and generate the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Masahiro Kawasaki , Toyokazu Sekiguchi

We examine cosmological perturbations in a dynamical theory of inflation in which an Abelian gauge field couples directly to the inflaton, breaking conformal invariance. When the coupling between the gauge field and the inflaton takes a…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-13 Timothy R. Dulaney , Moira I. Gresham

We consider the space-condensate inflation model to study the primordial gravitational waves generated in the early Universe. We calculate the energy spectrum of gravitational waves induced by the space-condensate inflation model for full…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Seoktae Koh , Bum-Hoon Lee , Gansukh Tumurtushaa

We investigate slow roll inflation and the creation of primordial density fluctuations in the framework of $f(Q,T)$ gravity. Our focus is on constraining the evolution of both the background and perturbations in this theory, specifically…

General Relativity and Quantum Cosmology · Physics 2026-02-09 Parviz Goodarzi

Quadratic gravity is a fourth-order (in derivatives) theory that can serve as an attractive upgrade to the standard description of gravity provided by General Relativity, thanks to its renormalizability and its built-in description of…

General Relativity and Quantum Cosmology · Physics 2025-05-30 Jisuke Kubo , Jeffrey Kuntz

We investigate the evolution of cosmological perturbations generated during de Sitter inflation in the conformal gravity. Primordial gravitational waves are composed of vector and tensor modes. We obtain the constant vector and tensor power…

General Relativity and Quantum Cosmology · Physics 2014-07-03 Yun Soo Myung , Taeyoon Moon

This paper investigates the effects of nonvanishing spatial curvature on the propagation of primordial gravitational waves produced during inflation. In particular, we consider tensor perturbations over a homogeneous and isotropic…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-29 Rocco D'Agostino , Matteo Califano , Nicola Menadeo , Daniele Vernieri

We analyze the effects of the holographic dark energy model in a single field slow-roll inflation, taking into account both the holographic and the dark radiation components. In particular, we obtain the background evolution and compute the…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Paola C. M. Delgado , Alexander Ganz , Chunshan Lin

We study the effects of a general type of features of the inflaton potential on the spectrum and bispectrum of primordial curvature perturbations. These features correspond to a discontinuity in the $n$-th order derivative of the potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-25 Alexander Gallego Cadavid
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