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Related papers: Warm DBI inflation with constant sound speed

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We consider warm inflation with a Dirac-Born-Infeld (DBI) kinetic term in which both the nonequilibrium dissipative particle production and the sound speed parameter slow the motion of the inflaton field. We find that a low sound speed…

High Energy Physics - Theory · Physics 2021-08-19 Meysam Motaharfar , Rudnei O. Ramos

We propose a warm inflationary model in the context of relativistic D-brane inflation in a warped throat, which has Dirac-Born-Infeld (DBI) kinetic term and is coupled to radiation through a dissipation term. The perturbation freezes at the…

High Energy Physics - Theory · Physics 2011-05-23 Yi-Fu Cai , James B. Dent , Damien A. Easson

In the present paper, we aim to generalize the constant-roll inflation in the non-canonical set-up, particularly in the context of scalar Dirac-Born-Infeld (DBI) theory which has emerged to be prospective candidate for describing inflation…

High Energy Physics - Theory · Physics 2018-07-05 Sayantani Lahiri

We investigate the power-law, intermediate, and logamediate inflationary models in the framework of DBI non-canonical scalar field with constant sound speed. In the DBI setting, we first represent the power spectrum of both scalar density…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 Roonak Amani , Kazem Rezazadeh , Asrin Abdolmaleki , Kayoomars Karami

We study mimetic gravity in the presence of a DBI-like term which is a non-canonical setup of the scalar field's derivatives. We consider two general cases with varying and constant sound speeds and construct the potentials for both the DBI…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-13 Kourosh Nozari , Narges Rashidi

In this paper, we consider two case examples of Dirac-Born-Infeld (DBI) generalizations of canonical large-field inflation models, characterized by a reduced sound speed, $c_{S} < 1$. The reduced speed of sound lowers the tensor-scalar…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Nina K. Stein , William H. Kinney

Dirac-Born-Infeld scalar field theories which appear in the context of inflation in string theory in general have a field dependent speed of sound. It is however possible to write down DBI models which possess exact solutions characterized…

Astrophysics · Physics 2009-06-23 Michal Spalinski

In Dirac-Born-Infeld inflation, changes in the sound speed that transiently break the slow roll approximation lead to features in the power spectrum. We develop and test the generalized slow roll approximation for calculating such effects…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 V Miranda , Wayne Hu , Peter Adshead

We study DBI inflation based upon a general model characterized by a power-law flow parameter $\epsilon(\phi)\propto\phi^{\alpha}$ and speed of sound $c_s(\phi)\propto\phi^{\beta}$, where $\alpha$ and $\beta$ are constants. We show that in…

General Relativity and Quantum Cosmology · Physics 2009-10-02 Dennis Bessada , William H. Kinney , Konstantinos Tzirakis

The scalar-tensor Dirac-Born-Infeld (DBI) inflation scenario provides a simple mechanism to reduce the large values of the boost factor associated with single field models with DBI action, whilst still being able to drive 60 efolds of…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-04 Joel M. Weller , Carsten van de Bruck , David F. Mota

We discuss a supersymmetric version of DBI (Dirac-Born-Infeld) inflation, which is a typical inflation model in string cosmology. The supersymmetric DBI action together with a superpotential always leads to correction terms associated with…

High Energy Physics - Theory · Physics 2015-06-05 Shin Sasaki , Masahide Yamaguchi , Daisuke Yokoyama

We study the K-Inflation models where the inflaton field has non-canonical kinetic term. In particular, we consider the Dirac-Born-Infeld (DBI) form for the kinetic energy of the inflaton field. We consider quadratic and quartic potentials…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 N. Chandrachani Devi , Akhilesh Nautiyal , Anjan A Sen

Picking out DBI scalar field as inflation, the slow-rolling inflationary scenario is studied by attributing an exponential time function to scale factor; known as intermediate inflation. The perturbation parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2017-08-15 N. Nazavari , A. Mohammadi , Z. Ossoulian , Kh. Saaidi

We study the de Sitter (dS) swampland conjecture in the Dirac-Born-Infeld (DBI) inflation model. We obtain the dS swampland bound for the relativistic regime using Bousso's entropy bound argument and proper distance. It restricts $m_{\rm…

High Energy Physics - Theory · Physics 2019-05-09 Min-Seok Seo

In this study, we explore the dynamics of warm inflation within a non-minimally coupled Peccei-Quinn (PQ) framework and evaluate its compatibility with the de Sitter Swampland Conjecture. Our model incorporates a PQ scalar field that is…

General Relativity and Quantum Cosmology · Physics 2024-10-17 Jureeporn Yuennan , Phongpichit Channuie , Davood Momeni

We study the preheating process in a model of DBI inflation with a DBI-type inflaton coupling to a canonical entropy field. At the end of inflation, the inflaton field oscillates around its vacuum which can arise from an infrared cutoff…

High Energy Physics - Theory · Physics 2013-08-12 Jun Zhang , Yifu Cai , Yun-Song Piao

We consider the Einstein equations within the DBI scenario for a spatially flat Friedmann-Robertson-Walker (FRW) spacetime without a cosmological constant. We derive the inflationary scenario by applying the symmetry transformations which…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-22 L. P. Chimento , R. Lazkoz , M. G. Richarte

We study the intermediate inflation in the mimetic Dirac-Born-Infeld model. By considering the scale factor as $a=a_{0}\exp(bt^{\beta})$, we show that in some ranges of the intermediate parameters $b$ and $\beta$, the model is free of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-27 Narges Rashidi , Kourosh Nozari

A characteristic of D-brane inflation is that fluctuations in the inflaton field can propagate at a speed significantly less than the speed of light. This yields observable effects that are distinct from those of single-field slow roll…

Astrophysics · Physics 2008-11-26 Hiranya V. Peiris , Daniel Baumann , Brett Friedman , Asantha Cooray

We consider an intermediate Dirac-Born-Infeld (DBI) inflationary model in the presence of a minimal measurable length in the theory. We show that, the presence of a minimal measurable length modifies the definitions of the scalar and tensor…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-02 Narges Rashidi , Maryam Roushan , Kourosh Nozari
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