Accelerating universes driven by bulk particles

Abstract

We consider our universe as a 3d domain wall embedded in a 5d dimensional Minkowski space-time. We address the problem of inflation and late time acceleration driven by bulk particles colliding with the 3d domain wall. The expansion of our universe is mainly related to these bulk particles. Since our universe tends to be permeated by a large number of isolated structures, as temperature diminishes with the expansion, we model our universe with a 3d domain wall with increasing internal structures. These structures could be unstable 2d domain walls evolving to fermi-balls which are candidates to cold dark matter. The momentum transfer of bulk particles colliding with the 3d domain wall is related to the reflection coefficient. We show a nontrivial dependence of the reflection coefficient with the number of internal dark matter structures inside the 3d domain wall. As the population of such structures increases the velocity of the domain wall expansion also increases. The expansion is exponential at early times and polynomial at late times. We connect this picture with string/M-theory by considering BPS 3d domain walls with structures which can appear through the bosonic sector of a five-dimensional supergravity theory.Comment: To appear in Phys. Rev. D, 16 pages, 3 eps figures, minor changes and references adde

Mirage effects on the brane

“…[24]. (4.42) where primes indicate derivatives with respect to r. Apart from the scalar field, we have included a negative cosmological constant −Λ in the bulk.…”

Late acceleration andw=−1crossing in induced gravity

“…The cosmological evolution in the ǫ = 1 branch of equation (25) is dominated by an effective cosmological constant at late times. The brane matter and the generalized dark radiation modify the leading exponential expansion.…”

“…In the standard case there is a black hole located at ℓ 0 = 0, so that the integrated mass is constant: M = M 0 . For this value our result (25) contains the known contribution characterized as dark radiation. For a general bulk content, the dark radiation term is replaced by the contribution M/(6π 2 M 3 ℓ 4 ).…”

“…Several examples of non-standard scaling are known [20,21,22]. Also, the energy exchange between the brane and the bulk may result in a complicated cosmological expansion [23,24,25].…”

Nonlinear two-field models from orbit equation deformations

“…In fact, the literature these days has plenty of models and applications of solitonic solutions in one and two dimensions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. For instance, those solutions can be used in order to investigate the formation of domain walls inside domain walls for the case of accelerating universes driven by bulk particles [17]. Furthermore, the case of braneworld scenarios described in five-dimensional space-time with warped geometry involving a single extra dimension, has received considerable attention recently [18,19].…”