Related papers: Degenerate and critical domain walls and accelerat…
To clarify observational consequence of bubble nucleations in inflationary era, we analyse dynamics of a spherical domain wall in an expanding universe. We consider a spherical shell of the domain wall with tension $\sigma$ collapsing in a…
The accelerated expansion of the universe is the most debatable cosmological scenario in the last two decades. Looking for the proper explanation of this scenario, researchers have presented a lot of proposals to discuss it. However,…
The expansion of the closed two-component universe has been considered. The potential barrier of the expansion has been investigated and its overcoming condition has been obtained. The restrictions on the Friedmann integrals, cosmological…
Cosmic acceleration may be the result of unknown physical processes involving either new fields in high energy physics or modifications of gravitation theory. In the latter case, such modifications are usually related to the existence of…
We present four-dimensional gauge theories in Minkowski spacetime which effectively generate in certain energy regimes five-dimensional warped geometries whereas, in general, the fifth dimension is latticized. After discussing in detail…
A gravity-driven inflation is shown to arise from a simple higher dimensional universe. In vacuum, the shear of $n>1$ contracting dimensions is able to inflate the remaining three spatial dimensions. Said another way, the expansion of the…
In this paper it is studied the cosmology of a homogeneous and isotropic spacetime endorsed with a conformally coupled massless scalar field. We find six different solutions of the Friedmann equation that represent six different types of…
Local and global gravitational effects induced by eternal vacuum domain walls are studied. We concentrate on thin walls between non-equal and non-positive cosmological constants on each side of the wall. These vacuum domain walls fall in…
We discuss the cosmology of a 3-brane embedded in a 5D bulk space-time with a cosmological constant when an intrinsic curvature Ricci scalar is included in the brane action. After deriving the `brane-Friedmann' equations for a Z_2…
We derive a kinetic Boltzmann equation characterizing the long-term statistical behavior of the turbulent dynamics of nonlinear interacting gravitational wave multipoles in Minkowski spacetime and show that, injecting a large number of…
This talk presents an overview of the brane cosmology scenario, based on the idea that our Universe is a 3-brane embedded in a five-dimensional anti-de Sitter bulk space-time. Special emphasis is put on the novel features of this scenario:…
In 1908, Minkowski put forward the idea that invariance under what we call today the Lorentz group, $GL(1,3, {\bf R})$, would be more meaningful in a four-dimensional space-time continuum. This suggestion implies that space and time are…
We use Hamiltonian methods to study curved domain walls and cosmologies. This leads naturally to first order equations for all domain walls and cosmologies foliated by slices of maximal symmetry. For Minkowski and AdS-sliced domain walls…
We show that the scalar-vacuum Brans-Dicke equations in 5D are equivalent to Brans-Dicke theory in 4D with a self interacting potential and an effective matter field. The cosmological implication, in the context of FRW models, is that the…
A model of the Universe as a mixture of a scalar (inflaton or rolling tachyon from the string theory) and a matter field (classical particles) is analyzed. The particles are created at the expense of the gravitational energy through an…
The compactification of M theory with time dependent hyperbolic internal space gives an effective scalar field with exponential potential which provides a transient acceleration in Einstein frame in four dimensions. Ordinary matter and…
We investigate the spacetime of a thick gravitating domain wall for a general potential $V(\Phi)$. Using general analytical arguments we show that all nontrivial solutions fall into two categories: those interpretable as an isolated domain…
We propose a new scenario for the bouncing universe in a simple five-dimensional braneworld model in the framework of Einstein-Gauss-Bonnet gravity, which works even with ordinary matter on the brane. In this scenario, the so-called branch…
Main aim of this work is to give a suitable explanation of present accelerating universe through an acceptable interactive dynamical cosmological model. A three-fluid cosmological model is introduced in the background of…
We find a cosmological solution corresponding to compactification of 10d supergravity on a warped conifold that easily circumvents `no-go' theorem given for a warped/flux compactification, providing new perspectives for the study of…