Brane‐bulk energy exchange and cosmological acceleration

Abstract

Abstract:The consequences for the brane cosmological evolution of energy exchange between the brane and the bulk are analyzed. A rich variety of brane cosmologies is obtained, depending on the precise mechanism of energy transfer, the equation of state of brane-matter and the spatial topology. An accelerating era is generically a feature of the solutions.

Dynamics of Dark Energy

“…The cosmology associated with these solutions predicts that the present dark-matter content of the universe may be significantly larger than that of a ΛCDM cosmology, its influence, being counterbalanced by the dark-radiation term. This is an interesting approach to dark energy, is well motivated by brane dynamics and has generated quite a bit of interest over the past few years [317,318] and for a review see [319].…”

Holography and brane–bulk energy exchange

“…(b) Tracking solutions where the mirage energy tracks the observable energy density [4] Further analysis and ansätze have been made in [20]- [26]. An exact solution was also found, describing the radiation of energy from the brane in the RS case [26], [34], [35].…”

“…To do this, we will review below the IR regularization of the gravitational (string) theory on AdS 5 . 4 Maldacena has conjectured [37] that string theory on AdS 5 × S 5 with N units of four-form flux is dual to N = 4 SU(N) Super Yang-Mills theory. The gauge theory has two dimensionless parameters: the number of colors N and the 't Hooft coupling λ = g 2 Y M N. They are related to the five-dimensional Planck scale M, the AdS 5 length ℓ and the string scale l s as…”

A classification of toroidal orientifold models

“…-if G contains no Z 2 -factors, the only contribution to the annulus amplitude is coming from the 99 strings. 4 We should mention that D7 and D3 branes are obtained in orientifold models where Ω acts together with a reflection element I 2 that gives a minus sign to the coordinates of one of the T 2 i torus.…”

“…Consistency and stability of the theory are assured if D-branes are introduced in a way that guarantees the cancellation of these tadpoles. R-R tadpole cancellation is equivalent to the vanishing of gauge charge in a compact space, whereas NS-tadpole cancellation is equivalent to the vanishing of forces in the D-brane/O-plane vacuum configuration [4].…”