Braneworld cosmological singularities
نویسندگان
چکیده
The purpose of this brief report is to present some results of our on-going project on the asymptotic behaviour of braneworld-type solutions on approach to their possible finite ‘time’ singularities. Cosmological singularities in such frameworks have served as means to attack the cosmological constant problem (see and references therein). The main mathematical tool of our analysis is the method of asymptotic splittings introduced in Ref. Below we study a model consisting of a 3−brane configuration embedded in a five dimensional bulk space with a scalar field being minimally coupled to the bulk and conformally coupled to the fields restricted on the brane. The total action is taken to be Stotal = Sbulk + Sbrane, where
منابع مشابه
A POSITIVE COSMOLOGICAL CONSTANT IN STRING THEORY THROUGH AdS/CFT WORMHOLES
There are two important examples of physical systems which violate the strong energy condition : Universes (like, it would seem, our own) with a positive cosmological constant, and wormholes. We suggest that a positive cosmological constant can be reconciled with string theory by considering wormholes in string backgrounds. This is argued in two directions : first, we show that brane-worlds wit...
متن کاملBouncing and Colliding Branes
In a braneworld description of our universe, we must allow for the possibility of having dynamical branes around the time of the big bang. Some properties of such domain walls in motion are discussed here, for example the ability of negative-tension domain walls to bounce off spacetime singularities and the consequences for cosmological perturbations. In this context, we will also review a coll...
متن کاملGauss-Bonnet braneworld cosmological effect on relic density of dark matter
In Gauss-Bonnet braneworld cosmology, the Friedmann equation of our four-dimensional universe on 3-brane is modified in a high energy regime (Gauss-Bonnet regime), while the standard expansion law is reproduced in low energies (standard regime). We investigate the Gauss-Bonnet braneworld cosmological effect on the thermal relic density of cold dark matter when the freeze-out of the dark matter ...
متن کاملConsistency equations in Randall-Sundrum cosmology: a test for braneworld inflation
In the context of an inflationary Randall-Sundrum Type II braneworld (RS2) we calculate spectral indices and amplitudes of cosmological scalar and tensor perturbations, up to second order in slow-roll parameters. Under very simple assumptions, extrapolating next-order formulas from first-order calculations in the case of a de Sitter brane, we see that the degeneracy between standard and branewo...
متن کاملBraneworld Black Holes in Cosmology and Astrophysics
The braneworld description of our universe entails a large extra dimension and a fundamental scale of gravity that might be lower by several orders of magnitude compared to the Planck scale. An interesting consequence of the braneworld scenario is in the nature of spherically symmetric vacuum solutions to the brane gravitational field equations which could represent black holes with properties ...
متن کامل