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Related papers: Brane World Inflation with Scalar and Tachyon Fiel…

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An intermediate inflationary universe model in the context of a generalized Chaplygin gas is considered. For the matter we consider two different energy densities; a standard scalar field and a tachyon field, respectively. In general, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Ramon Herrera , Marco Olivares , Nelson Videla

We examine the possibility of rolling tachyon to play the dual roll of inflaton at early epochs and dark matter at late times. We argue that enough inflation can be generated with the rolling tachyon either by invoking the large number of…

High Energy Physics - Theory · Physics 2008-11-26 M. Sami , Pravabati Chingangbam , Tabish Qureshi

We present uniform rate inflation in a modified $f(T, \mathcal{T}) $ gravity. It is found that early inflation can be realized even with a scalar field field with a quadratic potential and a negative cosmological constant. We construct…

General Relativity and Quantum Cosmology · Physics 2025-07-02 Priyanka Mandal , B. C. Paul

We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential…

General Relativity and Quantum Cosmology · Physics 2017-12-12 Y. Bisabr , F. Ahmadi

This paper investigates Starobinsky's model of inflation driven by the trace anomaly of conformally coupled matter fields. This model does not suffer from the problem of contrived initial conditions that occurs in most models of inflation…

High Energy Physics - Theory · Physics 2009-10-31 S. W. Hawking , T. Hertog , H. S. Reall

In this paper we present a model for accelerated expansion of the universe, both during inflation and the present stage of the expansion, from four dimensional $\mathcal{N}=1$ supergravity. We evaluate the tensor-to-scalar ratio ($r\approx…

High Energy Physics - Theory · Physics 2015-09-29 Ricardo C. G. Landim

Inflationary cosmology has provided a predictive and phenomenologically very successful scenario for early universe cosmology. Attempts to implement inflation using scalar fields, however, lead to models with serious conceptual problems. I…

Astrophysics · Physics 2007-05-23 Robert H. Brandenberger

The main aim of this paper is to provide a qualitative introduction to the cosmic inflation and its relationship with current cosmological observations. The inflationary model solves many of the fundamental problems that challenge the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-24 J. Alberto Vazquez , Luis E. Padilla , Tonatiuh Matos

We consider several classes of noncommutative inflationary models within an extended version of patch cosmological braneworlds, starting from a maximally invariant generalization of the action for scalar and tensor perturbations to a…

High Energy Physics - Theory · Physics 2009-11-10 Gianluca Calcagni

We propose a geometrical model of brane inflation where inflation is driven by the flux generated by opposing brane charges and terminated by the collision of the branes, with charge annihilation. We assume the collision process is…

High Energy Physics - Theory · Physics 2009-11-11 Sugumi Kanno , Jiro Soda , David Wands

We analyse the cosmological implications of brane-antibrane systems in string-theoretic orbifold and orientifold models. In a class of realistic models, consistency conditions require branes and antibranes to be stuck at different fixed…

High Energy Physics - Theory · Physics 2014-11-18 C. P. Burgess , P. Martineau , F. Quevedo , G. Rajesh , R. -J. Zhang

This paper investigates a scale-invariant inflationary model characterized by a scalar field non-minimally coupled to gravity and a curvature term quadratic in the Ricci scalar. The model's dynamic is analyzed using a full numerical…

High Energy Physics - Theory · Physics 2024-10-10 Mariaveronica De Angelis , Chiara Cecchini , Massimiliano Rinaldi

We examine some inflationary models based on modifications of gravity in the light of Planck 2015 data, such as the generalised Chaplygin inspired inflation, models based in $N=1$ supergravity and braneworld scenarios. We also show that,…

High Energy Physics - Theory · Physics 2018-06-06 Cláudio Gomes , Orfeu Bertolami , João G. Rosa

In this paper, we study inflation with {\alpha}-attractor potential in the RS braneworlds where high energy corrections to the Friedmann equation facilitate slow roll. In this scenario, we numerically investigate the inflationary parameters…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Nur Jaman , Kairat Myrzakulov

We study N=1 Supergravity inflation in the context of the braneworld scenario. Particular attention is paid to the problem of the onset of inflation at sub-Planckian field values and the ensued inflationary observables. We find that the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. C. Bento , O. Bertolami , A. A. Sen

We examine the behavior of an anisotropic brane-world in the presence of inflationary scalar fields. We show that, contrary to naive expectations, a large anisotropy does not adversely affect inflation. On the contrary, a large initial…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Roy Maartens , Varun Sahni , Tarun Deep Saini

We propose a scenario of the beginning of inflation in which the non-vacuum value of the scalar field that drives inflation develops dynamically due to the non-minimal coupling to gravity. In this scenario, inflation emerges as an…

High Energy Physics - Phenomenology · Physics 2016-09-06 M. V. Libanov , V. A. Rubakov , P. G. Tinyakov

At energies higher than the brane tension, the dynamics of a scalar field rolling down a potential are modified relative to the predictions of General Relativity. The modifications imply, among other things, that steeper potentials can be…

Astrophysics · Physics 2009-11-07 P. R. Ashcroft , C. van de Bruck , A. -C. Davis

We consider hybrid inflation in the braneworld scenario. In particular, we consider inflation in global supersymmetry with the D-terms in the scalar potential for the inflaton field to be the dominant ones (D-term inflation). We find that…

High Energy Physics - Phenomenology · Physics 2009-11-11 G. Panotopoulos

In this paper, we explore the equivalence between two theories, namely f(R) and scalar-tensor theories of gravity. We use this equivalence to explore several f(R) toy models focusing on the inflation epoch of the early universe. The study…

General Relativity and Quantum Cosmology · Physics 2018-11-21 Joseph Ntahompagaze , Jean Damascene Mbarubukeye , Shambel Sahlu , Amare Abebe