Five-dimensional Brans–Dicke M 1×R 3×S 1 cosmology with chameleon scalar field

Abstract

We investigate five-dimensional Brans-Dicke cosmology with spacetime described by the homogeneous, anisotropic and flat spacetime with the topology M 1 × R 3 × S 1 where S 1 is taken in the form of a circle. We conjecture throughout this letter that the extra-dimension compactifies as the visible dimensions expand like b(t) ≈ a −1 (t) and that the non-minimal coupling between the scalar field and the matter is of the form f (φ) ∝ φ 2 . The model gives rise to a transition from a decelerated epoch to an accelerated epoch for large values of the Brans-Dicke parameter ω. The model predicts crossing of the phantom divided barrier unless the universe is governed by a growing matter field.Keywords Brans-Dicke cosmology · Chameleon · Dark energy · Vacuum energy · Accelerated expansion · Phantom energy · Growing matter During the present decade, there have been considerable efforts in constructing realistic accelerating cosmological models dominated by dark energy (DE), either motivated by particle physics or by phenomenological reflections. The strong evidence confirming the low-redshift onset of the accelerated expansion of the cosmos comes directly from the CMBR dataset of the Three-Year WMAP observations and is indirectly supported by various other cosmological observations using combined WMAP data and data from the Supernova Legacy Survey of type SNeIa and large galaxy

Asymptotically Static Universe Dominated by Phantom Energy

“…We show that this law yields an interesting cosmological scenario. It is noteworthy that the variation of the Hubble parameter with the scalar field is not new, as they are motivated from generalised gravity theories and superstring arguments, and it was discussed in many cosmological theories through different contexts [26][27][28]. The true motivation to choose (12) is based on the observation that the Hubble parameter in the Friedmann equation (8) depends on first terms like φ, / φ φ and, besides, the presence of terms like / φ φ will simplify the calculation.…”

“…However, let us mention that in spite of all these theoretical attempts, the nature of dark energy is still enigmatic. The theory that we describe here generalises the chameleonic Brans-Dicke gravity [11,12] characterised by a non-minimal coupling between the scalar field and matter and differs as well from the author's work [13] characterised by the presence of an extra dimension. It is, in fact, a generalisation of the work done by de Souza and Braz and Jamil et al [14,15] by the facts that a scalar field coupled to the matter is present in the theory, the EoS parameter is time dependent and, in addition, we introduce a particular form of a scalar field-dependent Hubble parameter.…”

Statefinder Parameters for Different Dark Energy Models with Variable G Correction in Kaluza-Klein Cosmology

“…In [42][43][44][45][46][47][48][49][50] it was solved the field equations of the FRW universe with variable G and (see also [51][52][53] where was considered the flat KK universe with variable but keeping G fixed). There are many works on higher dimensional space-time also [54][55][56][57][58][59].…”

FRW models with particle creation in Brans-Dicke theory

“…Berman (2008) has discussed the shear and vorticity in an accelerating BD lambda-universe with torsion. El-Nabulsi (2010a, 2010b have investigated the Gauss-Bonnet corrections in modified BD theory and discussed their findings in detail.…”