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Related papers: Inflationary potentials in DBI models

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Here, generation of PBHs and secondary GWs from non-canonical inflation with quartic potential have been probed. It is illustrated that, quartic potential in non-canonical setup with a generalized power-law Lagrangian density can source a…

General Relativity and Quantum Cosmology · Physics 2024-02-08 Soma Heydari , Kayoomars Karami

Inflationary $\alpha$-attractor models in supergravity, which provide excellent fits to the latest observational data, are based on the Poincare disk hyperbolic geometry. We refine these models by constructing Kahler potentials with…

High Energy Physics - Theory · Physics 2015-09-23 John Joseph M. Carrasco , Renata Kallosh , Andrei Linde

A generalization of inflationary $\alpha$-attractor models (``polynomial $\alpha$-attractor'') was recently proposed by Kallosh and Linde, in which the potential involves logarithmic functions of the inflaton so that the derivative of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-06 Kei-ichiro Kubota , Hiroki Matsui , Takahiro Terada

A new inflationary scenario driven by a slowly-rolling homogeneous scalar field whose potential $V\left(\varphi\right)$ is given by a generalized exponential function is investigated. Within the {\it slow-roll} approximation we obtain the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-17 B. W. Ribeiro , I. M. Macêdo , F. C. Carvalho

We study models of inflation with two scalar fields and non-canonical kinetic terms, focusing on the case in which the curvature and isocurvature perturbations are strongly coupled to each other. In the regime where a heavy mode can be…

High Energy Physics - Theory · Physics 2011-03-10 Sera Cremonini , Zygmunt Lalak , Krzysztof Turzynski

Motivated by the idea that inflation occurs at the GUT symmetry breaking scale, in this paper we construct a new class of large field inflaton potentials where the inflaton starts with a power law potential; after initial period of relative…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

We study multi-field Dirac-Born-Infeld (DBI) inflation models, taking into account the NS-NS and R-R bulk fields present in generic flux compactifications. We compute the second-order action, which governs the behaviour of linear…

High Energy Physics - Theory · Physics 2010-05-12 David Langlois , Sebastien Renaux-Petel , Daniele A. Steer

We introduce a model of potential driven DBI Galileon inflation in background N=1,D=4 SUGRA. Starting from D4-$\bar{D4}$ brane-antibrane in the bulk N=2,D=5 SUGRA including quadratic Gauss-Bonnet corrections, we derive an effective N=1,D=4…

High Energy Physics - Theory · Physics 2015-03-20 Sayantan Choudhury , Supratik Pal

We present a complete computation of the scalar power spectrum in the \emph{inflation without inflaton} (IWI) framework, where the inflationary expansion is driven solely by a de~Sitter (dS) background and scalar fluctuations arise as…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Marisol Traforetti , Mariam Abdelaziz , Daniele Bertacca , Raul Jimenez , Sabino Matarrese , Angelo Ricciardone

The dilaton is a possible inflaton candidate following recent CMB data allowing a non-minimal coupling to the Ricci curvature scalar in the early Universe. In this paper, we introduce an approach that has seldom been used in the literature,…

High Energy Physics - Theory · Physics 2017-11-09 Alexey S. Koshelev , K. Sravan Kumar , Paulo Vargas Moniz

Simple monomial inflationary scenarios have been ruled out by recent observations. In this work we revisit the next simplest scenario, a single--field model where the scalar potential is a polynomial of degree four which features a concave…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Manuel Drees , Yong Xu

We consider inflation using a class of non-canonical Lagrangians for which the modification to the kinetic term depends on the field, but not its derivatives. We generalize the standard Hubble slow roll expansion to the non-canonical case…

Astrophysics · Physics 2010-10-27 Gabriela Barenboim , William H. Kinney

We present an inflationary universe model which utilizes two coupled real scalar fields. The inflation field $\phi$ experiences a first order phase transition and its potential dominates the energy density of the Universe during the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Fred C. Adams , Katherine Freese

We explore what can be said on the effective temperature and sound speed of a statistical ensemble of fluid phonons present at the onset of a conventional inflationary phase. The phonons are the actual normal modes of the gravitating and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Massimo Giovannini

Inflationary $\alpha$-attractor models can be naturally implemented in supergravity with hyperbolic geometry. They have stable predictions for observables, such as $n_s=1-{2/ N_e} $, assuming that the potential in terms of the original…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-20 Renata Kallosh , Andrei Linde

Most, if not all, scalar-tensor theories are equivalent to General Relativity with a disformally coupled matter sector. In extra-dimensional theories such a coupling can be understood as a result of induction of the metric on a brane that…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-22 Carsten van de Bruck , Tomi Koivisto , Chris Longden

We analyse the dynamics of spinodal decomposition in inflationary cosmology using the closed time path formalism of out of equilibrium quantum field theory combined with the non-perturbative Hartree approximation. In addition to a general…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Cormier , R. Holman

In non-canonical two-field inflation models, deviations from the canonical model can be captured by a parameter $\xi$. We show this parameter is usually one half of the slow-roll order and analytically calculate the primordial power spectra…

General Relativity and Quantum Cosmology · Physics 2017-12-06 Yun-Chao Wang , Towe Wang

Inflationary potentials are investigated for specific models in type IIB string theory via flux compactification. As concrete models, we investigate several cases where the internal spaces are weighted projective spaces. The models we…

High Energy Physics - Theory · Physics 2011-03-15 Sunggeun Lee , Soonkeon Nam

We study a generalized superconformal model that gives rise to a subcritical regime of $D$-term hybrid inflation. Exhibiting the model both in a Jordan frame and in the Einstein frame, the effective potential of the subcritical regime is…

High Energy Physics - Phenomenology · Physics 2022-01-07 Yoshihiro Gunji , Koji Ishiwata