相关论文: Of Bounces, Branes and Bounds

We examine several different types of five dimensional stationary spacetimes with bulk scalar fields and parallel 3-branes. We study different methods for avoiding the appearance of spacetime singularities in the bulk for models with and…

The maximal symmetry, or Perfect Cosmological Principle(PCP), that prevents AdS type spaces from degenerating into anti-inflationary collapse is argued to be unphysical. For example, the simple requirement that brane-bulk models should be…

We investigate a non-singular cosmological scenario in which uniform-rate inflation is realised on an anisotropic Shtanov-Sahni braneworld. The model naturally resolves the initial singularity resulting in an infinite number of smooth…

Bulk supergravity on a manifold with boundary must be supplemented by boundary conditions that preserve local supersymmetry. This "downstairs" picture has certain advantages over the equivalent "upstairs" picture, expressed in terms of…

A rich variety of brane cosmologies is obtained once one allows for energy exchange between the brane and the bulk, depending on the precise form of energy transfer, on the equation of state of matter on the brane and on the spatial…

The cosmology of a brane-universe embedded in a higher dimensional bulk spacetime presents some peculiarities not seen in ordinary (3+1) dimensional gravity. I summarize the current understanding, with emphasis on the suggestion by Randall…

Based on holographic arguments Tanaka and Emparan et al have claimed that large localized static black holes do not exist in the one-brane Randall-Sundrum model. If such black holes are time-dependent as they propose, there are potentially…

The Cobordism Conjecture states that any Quantum Gravity configuration admits, at topological level, a boundary ending spacetime. We study the dynamical realization of cobordism, as spacetime dependent solutions of Einstein gravity coupled…

In the framework of a five-dimensional model with one 3-brane and an infinite extra dimension, we discuss a process in which matter escapes from the brane and propagates into the bulk to arbitrarily large distances. An example is a decay of…

We propose new braneworld models arising from a scalar field in the bulk. In these examples, the induced on--brane line element is de Sitter (or anti de Sitter) and the bulk (five dimensional) Einstein equations can be exactly solved to…

A model of an emergent universe is obtained in brane world. Here the bulk energy is in the form of cosmological constant, while the brane consists of a fluid satisfying an equation of state of the form $p_{b}={1/3} \rho_{b}$, which is…

We study the asymptotic behavior of the bulk spacetimes with the negative cosmological constant in the context of the brane-world scenario. We show that, in Euclidean bulk, or in Lorentzian static bulk, some sequences of hypersurfaces with…

Birth of the brane world is studied using the Hamiltonian approach. It is shown that an inflating brane world can be created from nothing. The wave function of the universe obtained from the Wheeler de-Witt equation and the time-dependent…

The braneworld cosmological model was constructed by embedding a 3-brane into a higher dimensional bulk background geometry and the usual matter of our universe was assumed to be confined in the brane while the gravity can propagate in the…

We elaborate on the recently proposed static brane world scenario, where the effective 4-D cosmological constant is exponentially small when parallel 3-branes are far apart. We extend this result to a compactified model with two positive…

The cosmology of the Randall-Sundrum scenario for a positive tension brane in a 5-D Universe with localized gravity has been studied extensively recently. Here we extend it to more general situations. We consider the time-dependent…

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 this work we consider Randall-Sundrum brane-world type scenarios, in which the spacetime is described by a five-dimensional manifold with matter fields confined in a domain wall or three-brane. We present the results of a systematic…

A universe described by braneworlds is studied in a cyclic scenario. As expected such an oscillating universe will undergo turnarounds, whenever the phantom energy density reaches a critical value from either side. It is found that a…

We expand on the braneworld-black hole de Sitter model introduced in \cite{Rasulian} which is a proposal for constructing an effective de Sitter spacetime with no explicit dependence on brane tension or bulk cosmological constant. In this…