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Related papers: Assisted Inflation from Geometric Tachyon

200 papers

We adopt the double field natural inflation model motivated by the non-perturbative effects of supergravity and superstring theory to do the slow roll analysis. We show that when the parameters are suitably chosen, there exist ranges of…

General Relativity and Quantum Cosmology · Physics 2019-04-12 Ping Kwan Man Ellgan

We update predictions for observables in the "delicate" D3/anti-D3 inflationary model on the conifold. We use a full CMB likelihood calculation to assess goodness-of-fit, which is necessary because in this model the zeta power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-11 Kareem Marzouk , Alessandro Maraio , David Seery

The calculation of scalar gravitational and matter perturbations during multiple-field inflation valid to first order in slow roll is discussed. These fields may be the coordinates of a non-trivial field manifold and hence have non-minimal…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. J. W. van Tent , S. Groot Nibbelink

We analyze observational constraints on the parameter space of tachyonic inflation with a Gaussian potential and discuss some predictions of this scenario. As was shown by Kofman and Linde, it is extremely problematic to achieve the…

High Energy Physics - Theory · Physics 2008-11-26 Joris Raeymaekers

We have developed a formalism to study an inflationary scenario driven by a bulk inflaton in the two-brane system. The 4-dimensional low energy effective action is obtained using the gradient expansion method. It is also found that the dark…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Jiro Soda , Sugumi Kanno

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 investigate brane inflation, focusing on warm inflation realizations within a warped throat geometry. While the standard scenario relies on a single mobile $D3$-brane moving radially toward an anti-$D3$-brane at the tip of the throat, we…

High Energy Physics - Theory · Physics 2026-04-01 Dibya Chakraborty , Rudnei O. Ramos

We consider a simple inflation model with a complex scalar field coupled to gravity non-minimally. Both the modulus and the angular directions of the complex scalar are slowly rolling, leading to two-field inflation. The modulus direction…

High Energy Physics - Phenomenology · Physics 2015-05-28 Jinn-Ouk Gong , Hyun Min Lee

We explain how to obtain Klabanov-Strassler solution in the low-energy limit of type IIB superstring theory and describe slow-roll inflation on the system of parallely-separated D3-brane and D3bar-brane in the Klebanov-Strassler background.

High Energy Physics - Theory · Physics 2009-05-12 Yoonbai Kim , Hiroaki Nakajima , Kyungha Ryu , Hang Bae Kim

In scalar-tensor theories the scalar fields generically couple nontrivially to gravity. We study the observable properties of inflationary models with non-minimally coupled inflaton and Dirac-Born-Infeld (DBI) kinetic term. Within the…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Damien A. Easson , Shinji Mukohyama , Brian A. Powell

We investigate slow-roll inflation in a multi-field random Gaussian landscape. The landscape is assumed to be small-field, with a correlation length much smaller than the Planck scale. Inflation then typically occurs in small patches of the…

High Energy Physics - Theory · Physics 2018-02-13 Ali Masoumi , Alexander Vilenkin , Masaki Yamada

We investigate observational constraints on inflationary parameters in the context of an holographic cosmology with an induced gravity correction. We consider two situations where a universe is firstly filled with a scalar field and…

High Energy Physics - Theory · Physics 2020-04-21 Aatifa Bargach , Farida Bargach , Ahmed Errahmani , Taoufik Ouali

We present a mechanism for exit from inflation and reheating using the AdS/CFT correspondence. A cosmological evolution is induced on a probe D3-brane as it moves in a black D-brane background of type-0 string theory. If the tachyon field…

High Energy Physics - Theory · Physics 2009-11-10 E. Papantonopoulos , V. Zamarias

We obtain cosmological constraints on models of inflation which exhibit rapid roll solutions. Rapid roll attractors exist for potentials with large mass terms and are thus of interest for inflationary model building within string theory. We…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-15 Takeshi Kobayashi , Shinji Mukohyama , Brian A. Powell

We compare the simplest realistic brane inflationary model to recent cosmological data, including WMAP 3-year cosmic microwave background (CMB) results, Sloan Digital Sky Survey luminous red galaxies (SDSS LRG) power spectrum data and…

High Energy Physics - Theory · Physics 2010-10-27 Rachel Bean , Sarah E. Shandera , S. H. Henry Tye , Jiajun Xu

For the constant-roll tachyon inflation, we derive the analytical expressions for the scalar and tensor power spectra, the scalar and tensor spectral tilts and the tensor to scalar ratio up to the first order by using the method of Bessel…

General Relativity and Quantum Cosmology · Physics 2018-05-03 Qing Gao , Yungui Gong , Qin Fei

We study F-term inflation in M-theory with and without five-brane moduli fields. We show the slow rolling condition is not satisfied in M-theory without five-brane moduli fields, but it can be satisfied in the case with non-vanishing…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. M. Harun-or-Rashid , Tatsuo Kobayashi , Hitoshi Shimabukuro

In this paper the focus is on inflationary dynamics in the context of Einstein Gauss-Bonnet gravitational theories. We investigate the implications of the slow-roll condition on the slow-roll indices and we investigate how the inflationary…

General Relativity and Quantum Cosmology · Physics 2018-09-26 S. D. Odintsov , V. K. Oikonomou

We construct a model of inflation in string theory after carefully taking into account moduli stabilization. The setting is a warped compactification of Type IIB string theory in the presence of D3 and anti-D3-branes. The inflaton is the…

High Energy Physics - Theory · Physics 2014-11-18 Norihiro Iizuka , Sandip P. Trivedi

We explore the inflationary phase of a scalar field with a kinetic term non-minimally coupled to gravity. We find that one of the slow-roll conditions is naturally consequence of the equation of motion of the scalar field. Thus, slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-16 Amir Ghalee