相关论文: Stable, Time-Dependent, Exact Solutions for Brane …
We present new solutions of higher dimensional Einstein's equations with a cosmological constant that localize gravity on branes which are transverse to Ricci-flat manifolds or to homogeneous spaces with topologically non-trivial solutions…
We investigate singular geometries which can be associated with warped branes in arbitrary dimensions. If the brane tension is allowed to be variable, the extremum condition for the action requires additional constraints beyond the solution…
Large extra dimensional theories attempt to solve the hierarchy problem by assuming that the fundamental scale of the theory is at the electroweak scale. This requires the size of the extra dimensions to be stabilized at a scale which is…
We study the cosmology of models with four space and one time dimension where our universe is a 3-brane and report a few results which extend existing work in several directions. Assuming a stable fifth dimension, we obtain a solution for…
In the context of brane-world models, we pursue the question of the existence of 5-dimensional solutions describing regular black holes localised close to the brane. Employing a perturbed Vaidya-type line-element embedded in a warped fifth…
We discuss a new solution, admitting the existence of dS_{4} branes, in five-dimensional Brans-Dicke theory. It is shown that, due to a special form of a bulk scalar field potential, for certain values of the model parameters the effective…
We study cosmological dynamics and phase space of a scalar field localized on the DGP brane. We consider both the minimally and nonminimally coupled scalar quintessence and phantom fields on the brane. In the nonminimal case, the scalar…
A generalized version of the Randall-Sundrum model-2 with different cosmological constants on each side of a brane has been discussed. A possibility of replacing the singular brane by a configuration of a scalar field has been also…
In this paper, we study the implementation of brane worlds in type II string theory. Starting with the NS/NS sector of type II string, we first compactify the $(D+d_{+} + d_{-})$-dimensional spacetime, and reduce the corresponding action to…
We study a smooth cosmological solution within a generalized 5D standing wave braneworld modeled by gravity and a phantom scalar field. In this model the 3-brane is anisotropically warped along its spatial dimensions and contains a novel…
We point out that the potential of Goldberger and Wise for stabilizing the distance between two 3-branes, separated from each other along an extra dimension with a warp factor, has a metastable minimum when the branes are infinitely…
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…
Hubble expansion in warped braneworld model is addressed in presence of more than one warped extra dimensions. It is shown that while the expansion depends on all the moduli, an exponential nature of the expansion of the scale factor…
We present a class of dynamical solutions in a D-dimensional gravitational theory coupled to a dilaton, a form field strength, and a cosmological constant. We find that for any D due to the presence of a cosmological constant, the metric of…
We investigate the scalar metric perturbations about a de Sitter brane universe in a 5-dimensional anti de Sitter bulk. We compare the master-variable formalism, describing metric perturbations in a 5-dimensional longitudinal gauge, with…
Orbifold branes in string theory are investigated, and the general field equations on the branes are given explicitly for type II and heterotic string. It is shown that the effective cosmological constant on each of the two branes can be…
We consider cosmological two-brane models with AdS bulk, for which the radion, i.e. the separation between the two branes, is time dependent. In the case of two de Sitter branes (including Minkowski branes as a limiting case), we compute…
We consider multidimensional gravitational models with a nonlinear scalar curvature term and form fields in the action functional. In our scenario it is assumed that the higher dimensional spacetime undergoes a spontaneous compactification…
We analyze a class of 5D models where a 3 brane is generated by a bulk scalar field non minimally coupled to gravity. We show that perturbative stability of such branes is normally guaranteed although non minimal couplings are not innocuous…
We present a new 3-brane solution to Einstein's equations in (1+5)-spacetime with a negative bulk cosmological constant. This solution is a stringlike defect solution with decreasing scale function approaching a finite non-zero value in the…