Related papers: Regularization of conical singularities in warped …
We report the results of a study on the dynamical compactification of spatially flat cosmological models in Einstein-Gauss-Bonnet gravity. The analysis was performed in the arbitrary dimension in order to be more general. We consider both…
We construct a regular five-dimensional brane-world with localised gravity on a flat 3-brane. The matter content in the bulk is parametrised by an analog of a non-linear fluid with equation of state $p=\gamma\rho^\lambda$ between the…
Warped compactifications with branes provide a new approach to the hierarchy problem and generate a diversity of four-dimensional thresholds. We investigate the relationships between these scales, which fall into two classes. Geometrical…
We study a recently proposed model, where a codimension one brane is wrapped around the axis of symmetry of an internal two dimensional space compactified by a flux. This construction is free from the problems which plague delta-like,…
Colliding branes without $Z_{2}$ symmetry and the formation of spacetime singularities in string theory are studied. After developing the general formulas to describe such events, we study a particular class of exact solutions first in the…
We study spacetime singularities in a general five-dimensional braneworld with curved branes satisfying four-dimensional maximal symmetry. The bulk is supported by an analog of perfect fluid with the time replaced by the extra coordinate.…
We consider a class of warped higher dimensional brane models with topology $M \times \Sigma \times S^1/Z_2$, where $\Sigma$ is a $D_2$ dimensional manifold. Two branes of codimension one are embedded in such a bulk space-time and sit at…
We compute how threshold effects obtained by integrating out a heavy particle localized on a codimension-2 brane influence the properties of the brane and the bulk fields it sources in D=d+2 dimensions. We do so using a recently developed…
We study the classical dynamics of the universe undergoing a transition from contraction to expansion through a big bang singularity. The dynamics is described by a system of differential equations for a set of physical quantities, such as…
We derive a solution of the gravitational equations which leads to a braneworld scenario in six dimensions using a global cosmic string solution in a low energy effective string theory framework. The final spacetime is composed by one…
Topology-changing transitions between vacua of different effective dimensionality are studied in the context of a 6-dimensional Einstein-Maxwell theory. The landscape of this theory includes a $6d$ de Sitter vacuum ($dS_6$), a number of…
The single 3-brane brane world at six dimension is examined when the extra dimensions are not compact. Although the warp factor diverges at the asymptotic region of the extra dimension, the normalizable zero mode and higher KK spectrum…
We obtain the effective gravitational equations on the codimension-2 and codimension-1 branes in the cascading gravity model. We then apply our formulation to the cosmological case and obtain the effective Friedmann equations on the…
We present the general regular warped solution with 4D Minkowski spacetime in six-dimensional gauged supergravity. In this framework, we can easily embed multiple conical branes into the warped geometry by choosing an undetermined…
Recently we proposed that K fields, that is, fields with a non-standard kinetic term, may provide a mechanism for the generation of thick branes, based on the following observations. Firstly, K field theories allow for soliton solutions…
We re-consider the self tuning idea in brane world models of finite volume. We notice that in a large class of self tuning models, the four dimensional physics is sensitive to the vacuum energy on the brane. In particular the…
We investigate non-local dualities between suitably compactified higher-dimensional Einstein gravity and supergravities which can be revealed if one reinterprets the dualised Kaluza-Klein two-forms in $D>4$ as antisymmetric forms belonging…
The `braneworld' (described by the usual worldvolume action) is a D dimensional timelike surface embedded in a N dimensional ($N>D$) warped, nonfactorisable spacetime. We first address the conditions on the warp factor required to have an…
Revisiting Einstein's gravitational theory, we build a five-dimensional braneworld. Within this framework, one announces the appearance of symmetric and asymmetric domain walls. Furthermore, it examines the emergent four-dimensional gravity…
We investigate the classical stability of non-supersymmetric Freund-Rubin compactifications of Type IIB string theory on a product of three-dimensional Einstein spaces A_3 x B_3 with both NS-NS and R-R three-form fluxes turned on through…