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We present our recent work on brane world models with a non-minimally coupled scalar field. In [9] we examined the stability of these models against scalar field perturbations and we discussed possible physical implications, while in [10]…

High Energy Physics - Theory · Physics 2007-05-23 K. Farakos , P. Pasipoularides

We consider two alternative dark energy models: a Lorentz invariance preserving model with a nonminimally coupled scalar field and a Lorentz invariance violating model with a minimally coupled scalar field. We study accelerated expansion…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Kourosh Nozari , S. Davood Sadatian

We have studied a DGP-inspired braneworld scenario where the idea of Lorentz invariance violation has been combined into a specifying preferred frame that embed a dynamical normal vector field to brane. We propose the Lorentz violating DGP…

General Relativity and Quantum Cosmology · Physics 2012-08-16 S. Davood Sadatian

Recent developments in the physics of extra dimensions have opened up new avenues to test such theories. We review cosmological aspects of brane world scenarios such as the Randall--Sundrum brane model and two--brane systems with a bulk…

High Energy Physics - Theory · Physics 2008-11-26 Philippe Brax , Carsten van de Bruck , Anne--Christine Davis

We study cosmological implications of a Lorentz invariance violating DGP-inspired braneworld scenario. A minimally coupled scalar field and a single, fixed-norm, Lorentz-violating timelike vector field within an interactive picture provide…

General Relativity and Quantum Cosmology · Physics 2009-02-12 Kourosh Nozari , S. Davood Sadatian

We investigate aspects of cosmology in brane world theories with a bulk scalar field. We concentrate on a recent model motivated from supergravity in singular spaces. After discussing the background evolution of such a brane-world, we…

High Energy Physics - Theory · Physics 2014-11-18 P. Brax , C. van de Bruck , A. C. Davis

We examine the scenario of non-minimally coupled relativistic fluid and $k$-essence scalar field in a flat Friedmann-Lemaitre-Robertson-Walker universe. By adding a non-minimal coupling term in the Lagrangian level, we study the variation…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Anirban Chatterjee , Saddam Hussain , Kaushik Bhattacharya

Many candidate fundamental theories contain scalar fields that can acquire spacetime-varying expectation values in a cosmological context. Such scalars typically obey Lorentz-violating effective dispersion relations. We illustrate this fact…

Astrophysics · Physics 2009-11-10 Orfeu Bertolami , Ralf Lehnert , Robertus Potting , Andre Ribeiro

We investigate the consequences of non-minimal gravitational coupling to matter and study how it differs from the case of minimal coupling by choosing certain simple forms for the nature of coupling, The values of the parameters are…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-03 Shruti Thakur , Anjan A Sen , T. R. Seshadri

We present solutions for the late time evolution of cosmological tensor and scalar perturbations in a single-Randall-Sundrum brane world model. Assuming that the bulk is anti-de Sitter spacetime, the solutions for cosmological perturbations…

Astrophysics · Physics 2009-11-10 Kazuya Koyama

We deal with relativistic models described by a single real scalar field, searching for topological structures that behave asymmetrically, connecting minima with distinct profile. We use such features to build a new braneworld scenario, in…

High Energy Physics - Theory · Physics 2015-11-06 D. Bazeia , M. A. Marques , R. Menezes

We study a model of scalar field with kinetic terms non-minimally coupled to to the curvature, and the scalar field coupled to the Gauss Bonnet 4-dimensional invariant. A variety of solutions are found, giving rise to different cosmological…

General Relativity and Quantum Cosmology · Physics 2015-05-30 L. N. Granda

Cosmological consequences of the brane world scenario are reviewed in a pedagogical manner. According to the brane world idea, the standard model particles are confined on a hyper--surface (a so--called brane), which is embedded in a…

High Energy Physics - Theory · Physics 2011-07-19 Philippe Brax , Carsten van de Bruck

Recent developments in the theory of extra dimensions have opened up avenues to confront such theories with cosmological tests. We discuss a brane-world model with a bulk scalar field, motivated by supergravity. The low-energy effective…

Astrophysics · Physics 2009-11-10 A. -C. Davis , Ph. Brax , C. van de Bruck

We consider the cosmological evolution of a brane in the presence of a bulk scalar field coupled to the Ricci scalar through a term f(\phi)R. We derive the generalized Friedmann equation on the brane in the presence of arbitrary brane and…

High Energy Physics - Theory · Physics 2008-11-26 C. Bogdanos , A. Dimitriadis , K. Tamvakis

We study cosmological consequences of the noncommutative approach to the standard model. Neglecting the nonminimal coupling of the Higgs field to the curvature, noncommutative corrections to Einstein's equations are present only for…

High Energy Physics - Theory · Physics 2010-05-12 William Nelson , Mairi Sakellariadou

We construct a DGP inspired braneworld scenario where a scalar field non-minimally coupled to the induced Ricci curvature is present on the brane. First we investigate the status of gravitational potential with non-minimal coupling and…

High Energy Physics - Theory · Physics 2009-06-11 Kourosh Nozari

We study the case of brane world models with an additional Gauss-Bonnet term in the presence of a bulk scalar field which interacts non-minimally with gravity, via a possible interaction term of the form $-1/2 \xi R \phi^2$. The Einstein…

High Energy Physics - Theory · Physics 2008-11-26 K. Farakos , P. Pasipoularides

We present a new approximation method for solving the equations of motion for cosmological tensor perturbations in a Randall-Sundrum brane-world model of the type with one brane in a five-dimensional anti-de Sitter spacetime. This method…

High Energy Physics - Theory · Physics 2010-05-12 Richard A. Battye , Andrew Mennim

Motivated by the dimensional asymmetry characteristic of braneworlds, we populate the bulk spacetime with matter scalar fields, both real and complex, and couple them non-minimally to gravity. We derive the effective equations of motion on…

High Energy Physics - Theory · Physics 2009-04-14 Orfeu Bertolami , Carla Carvalho
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