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Related papers: Anisotropic inflation with a non-minimally coupled…

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We revisit the idea of generating primordial anisotropies at the end of inflation in models of inflation with gauge fields. To be specific we consider the charged hybrid inflation model where the waterfall field is charged under a U(1)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Razieh Emami , Hassan Firouzjahi

We study an inflationary scenario with a two-form field to which an inflaton couples non-trivially. First, we show that anisotropic inflation can be realized as an attractor solution and that the two-form hair remains during inflation. A…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-16 Junko Ohashi , Jiro Soda , Shinji Tsujikawa

A generic feature of viable $F(R)$ gravity is investigated: It is demonstrated that during the matter dominated era the large frequency oscillations of the effective dark energy may influence the behavior of higher derivatives of the Hubble…

General Relativity and Quantum Cosmology · Physics 2012-12-14 Kazuharu Bamba , Antonio Lopez-Revelles , R. Myrzakulov , S. D. Odintsov , L. Sebastiani

In this paper, we consider a nonminimal coupling model between gravity and nonlinear electrodynamics with cosmological constant. This cosmological model is designed to account for both the inflationary epoch of the early universe and the…

General Relativity and Quantum Cosmology · Physics 2024-10-10 Chilwatun Nasiroh , Ramy F. Izzah , Fiki T. Akbar , Bobby E. Gunara

We study constant-roll inflation in the presence of a gauge field coupled to an inflaton. By imposing the constant anisotropy condition, we find new exact anisotropic constant-roll inflationary solutions which include anisotropic power-law…

High Energy Physics - Theory · Physics 2018-02-13 Asuka Ito , Jiro Soda

In this paper, we study a constant-roll inflationary model in the presence of a noncommutative parameter with a homogeneous scalar field minimally coupled to gravity. The specific noncommutative inflation conditions proposed new…

High Energy Physics - Theory · Physics 2023-02-14 J. Sadeghi , S. Noori Gashti

In the framework of Born-Infeld inspired gravity theories, which deviates from General Relativity (GR) in the high curvature regime, we discuss the viability of Cosmic Inflation without scalar fields. For energy densities higher than the…

General Relativity and Quantum Cosmology · Physics 2016-03-10 Jose Beltran Jimenez , Lavinia Heisenberg , Gonzalo J. Olmo , Christophe Ringeval

We study an inflationary scenario with a vector impurity. We show that the universe undergoes anisotropic inflationary expansion due to a preferred direction determined by the vector. Using the slow-roll approximation, we find a formula to…

High Energy Physics - Phenomenology · Physics 2008-11-26 Sugumi Kanno , Masashi Kimura , Jiro Soda , Shuichiro Yokoyama

We study a supergravity model of inflation essentially depending on one parameter which can be identified with the slope of the potential at the origin. In this type of models the inflaton rolls at high energy from negative values and a…

Astrophysics · Physics 2009-11-10 G. German , A. de la Macorra

We provide an explicit solution representing an anisotropic power law inflation within the framework of rolling tachyon model. This is generated by allowing a non-minimal coupling between the tachyon and the world-volume gauge field on…

High Energy Physics - Theory · Physics 2012-01-25 Samrat Bhowmick , Sudipta Mukherji

The present work is related to anisotropic cosmological evolution in metric $f(R)$ theory of gravity. The initial part of the paper develops the general cosmological dynamics of homogeneous anisotropic Bianchi-I spacetime in $f(R)$…

General Relativity and Quantum Cosmology · Physics 2019-01-23 Kaushik Bhattacharya , Saikat Chakraborty

We consider models of inflation with U(1) gauge fields and charged scalar fields including symmetry breaking potential, chaotic inflation and hybrid inflation. We show that there exist attractor solutions where the anisotropies produced…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-18 Razieh Emami , Hassan Firouzjahi , S. M. Sadegh Movahed , Moslem Zarei

We review cosmology in non-minimal Yang-Mills/Maxwell theory, in which the Yang-Mills/electromagnetic field couples to a function of the scalar curvature. We show that power-law inflation can be realized due to the non-minimal gravitational…

High Energy Physics - Theory · Physics 2008-11-09 Kazuharu Bamba , Shin'ichi Nojiri

Recently an inflationary model with a vector field coupled to the inflaton was proposed and the phenomenology studied for the Bianchi type I spacetime. It was found that the model demonstrates a counter-example to the cosmic no-hair theorem…

General Relativity and Quantum Cosmology · Physics 2011-12-22 Sigbjørn Hervik , David F. Mota , Mikjel Thorsrud

In the framework of geometrothermodynamics, we explore how to construct an inflationary cosmic fluid without requiring inflaton fields. To do so, we employ standard radiation and matter as barotropic background, speculating on the existence…

General Relativity and Quantum Cosmology · Physics 2024-07-03 Jesus Anaya-Galeana , Orlando Luongo , Hernando Quevedo

We study an inflationary scenario with a vector field coupled with an inflaton field and show that the inflationary universe is endowed with anisotropy for a wide range of coupling functions. This anisotropic inflation is a tracking…

High Energy Physics - Theory · Physics 2009-06-30 Masa-aki Watanabe , Sugumi Kanno , Jiro Soda

We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a $U(1)$ gauge field. Primordial anisotropies are generated either actively during inflation or from…

High Energy Physics - Theory · Physics 2015-06-17 Ali Akbar Abolhasani , Razieh Emami , Hassan Firouzjahi

Anisotropic inflation is a model succeeded in explaining statistical anisotropy. Warm inflation is a model succeeded in providing a mechanism of reheating during inflation. We study anisotropic warm inflation focusing on the cosmic no-hair…

High Energy Physics - Theory · Physics 2023-06-09 Sugumi Kanno , Ann Mukuno , Jiro Soda , Kazushige Ueda

We propose the study of constant-roll inflation in $F(R)$ gravity. We use two different approaches, one that relates an $F(R)$ gravity to well known scalar models of constant-roll and a second that examines directly the constant-roll…

General Relativity and Quantum Cosmology · Physics 2017-12-06 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

Solid inflation is an effective field theory of inflation in which isotropy and homogeneity are accomplished via a specific combination of anisotropic sources (three scalar fields that individually break isotropy). This results in specific…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-11 Nicola Bartolo , Marco Peloso , Angelo Ricciardone , Caner Unal