Related papers: Varying Fundamental Constants from a String-inspir…
The conditions for the existence and stability of cosmological power-law scaling solutions are established when the Einstein-Hilbert action is modified by the inclusion of a function of the Gauss-Bonnet curvature invariant. The general form…
We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time. The standard model matter fields live only on the 4D brane. The change of vacuum energy on the brane just gives rise to dynamical…
We study a codimension 2 braneworld in the Einstein-Gauss-Bonnet gravity. In the linear regime, we show the conventional Einstein gravity can be recovered on the brane. While, in the nonlinear regime, we find corrections due to the…
We analyze the cosmology of the Randall-Sundrum model and that of compact brane models in general in the presence of a radius stabilization mechanism. We find that the expansion of our universe is generically in agreement with the expected…
We present an effective four-dimensional formulation of the laws of gravity that respects the main features of a higher (five)-dimensional scenario of Randall-Sundrum type. The geometrical structure of the theory is that of a…
In this thesis, we explore three phenomenological alternatives to the current paradigm of the standard inflationary big bang scenario. The three alternative themes are spin torsion (or Einstein-Cartan-Kibble-Sciama) theories, extra…
The estimation of the cosmological constant in inflationary Brane New World models is done. It is shown that basically it is quite large, of the same order as in anomaly-driven inflation. However, for some fine-tuning of bulk gravitational…
In the present paper the gauge-invariant formalism is developed for perturbations of the brane-world model in which our universe is realized as a boundary of a higher-dimensional spacetime. For the background model in which the bulk…
This work deals with braneworld models driven by real scalar fields with nonstandard dynamics. We develop the first-order formalism for models with standard gravity but with the scalar fields having generalized dynamics. We illustrate the…
We discuss the possibility of a dynamical solution to the cosmological constant problem in the contaxt of six-dimensional Einstein-Maxwell theory. A definite answer requires an understanding of the full bulk cosmology in the early universe,…
The braneworlds models were inspired partly by Kaluza-Klein's theory, where both the gravitational and the gauge fields are obtained from the geometry of a higher dimensional space. The positive aspects of these models consist in…
Within the mini-superspace model, brane-like cosmology means performing the variation with respect to the embedding (Minkowski) time $\tau$ before fixing the cosmic (Einstein) time $t$. The departure from Einstein limit is parameterized by…
In the present paper, we briefly review recent studies of second-order gravitational perturbations in braneworld models. After we consider the possibility of pathological behavior of gravity at higher orders of perturbation, second-order…
The stability of Einstein static universe against homogeneous scalar perturbations in the context of braneworld scenario is investigated. The stability regions are obtained in terms of the constant geometric linear equation of state…
In this work we deal with the spacetime shaped by a straight cosmic string, emerging from local gauge theories, in the braneworld gravity context. We search for physical consequences of string features due to the modified gravitational…
We consider 5-dimensional spacetimes of constant 3-dimensional spatial curvature in the presence of a bulk cosmological constant. We find the general solution of such a configuration in the presence of a Gauss-Bonnet term. Two classes of…
In this paper we modify the EiBI model to realize a varying cosmological constant which is determined by matter distribution. We find that the Newton's constant is also variable and its change is related to the change of cosmological…
We discuss D-braneworld cosmology, that is, the brane is described by the Born-Infeld action. Compared with the usual Randall-Sundrum braneworld cosmology where the brane action is the Nambu-Goto one, we can see some drastic changes at the…
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…
The braneworld scenario is studied and the effective action of 3-brane living in 5-dim. Minkowski space is constructed. This action is proved to be invariant under spontaneously broken scale and Weyl symmetries and to encode a model of…