Related papers: Bad News on the Brane
My research work can be classified into two parts namely, (i) Cosmological phenomena with varying speed of light and (ii) Gravitational collapse and black holes. We have investigated several cosmological phenomena when velocity of light…
Various attempts to go beyond the theory of General Relativity start from the assumption that spacetime is not a 4-dimensional but rather a higher-dimensional manifold. Among others, braneworld scenarios postulate that the spacetime we…
We consider the four dimensional discontinuity generated by two identical pieces of a five dimensional space pasted along their edge (that is a "brane" in a "$Z_2$-symmetric" "bulk"). Using a four plus one decomposition of the Riemann…
In brane world models our universe is considered as a brane imbedded into a higher dimensional space. We discuss the behaviour of geodesics in the Randall-Sundrum background and point out that free massive particles cannot move along the…
An analysis of a spherically symmetric braneworld configuration is performed when the intrinsic curvature scalar is included in the bulk action. In the case when the electric part of the Weyl tensor is zero, all the exterior solutions are…
Using the method of asymptotic splittings, the possible singularity structures and the corresponding asymptotic behavior of a 3-brane in a five-dimensional bulk are classified, in the case where the bulk field content is parametrized by an…
In the Randall-Sundrum scenario we investigate the dynamics of a spherically symmetric 3-brane world when matter fields are present in the bulk. To analyze the 5-dimensional Einstein equations we employ a global conformal transformation…
Within the framework of braneworlds, several interesting physical effects can be described in a wide range of energy scales, starting from high-energy physics to cosmology and low-energy physics. An usual way to generate a thick braneworld…
We analyze the observational constraints on brane-world cosmology whereby the universe is described as a three-brane embedded in a five-dimensional anti-de Sitter space. In this brane-universe cosmology, the Friedmann equation is modified…
We consider a static brane in the background of a topological black hole, in arbitrary dimensions. For hyperbolic horizons, we find a solution only when the black hole mass assumes its minimum negative value. In this case, the tension of…
We consider a dynamical two-brane in a four dimensional black hole background with scalar hair. At high temperature this black hole goes through a phase transition by radiating away the scalar. The end phase is a topological…
In brane-world cosmology gravitational waves can propagate in the higher dimensions (i.e., in the `bulk'). In some appropriate regimes the bulk gravitational waves may be approximated by plane waves. We systematically study five-dimensional…
We report on explicit cosmological solutions within the framework of an inflating de Sitter brane embedded in five- and ten-dimensional bulk spacetimes. In the specific example we study the brane tension is induced by the curvature related…
The singularity structure and the corresponding asymptotic behavior of a 3-brane coupled to a scalar field in a five dimensional bulk is analyzed in full generality, using the method of asymptotic splittings. It is shown that the collapse…
We study the evolution of both scalar and tensor cosmological perturbations in a Randall-Sundrum braneworld having an arbitrary expansion history. We adopt a four dimensional point of view where the degrees of freedom on the brane…
We look for spherically symmetric star or black hole solutions on a Randall-Sundrum brane from the perspective of the bulk. We take a known bulk solution, and analyse possible braneworld trajectories within it that correspond, from the…
The behavior of the angular velocity of a test particle moving in a stable circular orbit in the vacuum on the brane is considered. In the brane world scenario, the four dimensional effective Einstein equation acquire extra terms, called…
In this work, we review and extend the so-called consistency conditions for the existence of a braneworld scenario in arbitrary dimensions in the Brans-Dicke (BD) gravitational theory. After that, we consider the particular case of a…
We discuss the cosmological evolution of a braneworld in five dimensional Gauss-Bonnet gravity. Our discussion allows the fifth (bulk) dimension to be space-like as well as time-like. The resulting equations of motion have the form of a…
We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time with a $Z_2$ symmetry in the presence of a massless scalar field. The standard model matter fields live only on the 4D brane. The…