We derive the effective four-dimensional gravity action in the RandallSundrum scenario in which two 3-branes of opposite tension reside in a fivedimensional spacetime. The dimensional reduction with the Ansatz for the radion field by Charmousis et al., which solves five-dimensional linearized field equations, results in a class of scalar-tensor gravity theories. In the limit of vanishing radion...

In the Brans-Dicke theory the Planck mass is replaced by a dynamical scalar field. We consider here the supersymmetric analogous of this mechanism replacing in the supergravity Lagrangian the Planck mass with a chiral superfield. This analysis is motivated by the research of possible connections between supersymmetric Dark Matter scenarios and Dark Energy models based on Brans-Dicke-like theori...

We have shown that the dynamics of the scalar field φ(x) = “G−1(x)” in BransDicke theories of gravity makes the surface area of the black hole horizon oscillatory during its dynamical evolution. It explicitly explains why the area theorem does not hold in Brans-Dicke theory. However, we show that there exists a certain non-decreasing quantity defined on the event horizon which is proportional t...

The spectra of relic gravitational waves produced as a result of cosmological expansion of the inflationary models are derived in Brans-Dicke (BD)theory of gravity.The time dependence of the very early Hubble parameter and matter energy density are derived from frequency dependent spectrum of relic gravitational waves.Also it is found that Brans-Dicke scalar field contributes to the energy dens...

We study spherically symmetric solutions to the Jordan-Brans-Dicke field equations under the assumption that the space-time may possess an arbitrary number of spatial dimensions. Assuming a perfect fluid with the equation of state p = ερ, we show that there are static interior nontrivial solutions in three dimensional Jordan-Brans-Dicke gravity theory.

We have solved Cosmological Gravitational Wave(GW) equation in the frame work of Gen-eralised Brans-Dicke(GBD) theory for all epochs of the Universe.The solutions are expresed in terms of the present value of the Brans-Dicke coupling parameter ω(φ).It is seen that the solutions represent travelling growing modes for negative values of ω 0 for all epochs of the Universe.

We study cosmological applications of the holographic energy density. Considering the holographic energy density as a dynamical cosmological constant, we need the Brans-Dicke theory as a dynamical framework instead of general relativity. In this case we use the Bianchi identity as a consistency relation to obtain physical solutions. It is shown that the future event horizon as the IR cutoff pro...

We consider a locally supersymmetric theory where the Planck mass is replaced by a dynamical superfield. This model can be thought of as the Minimal Supersymmetric extension of the Brans-Dicke theory (MSBD). The motivation that underlies this analysis is the research of possible connections between Dark Energy models based on Brans-Dicke-like theories and supersymmetric Dark Matter scenarios. W...

We study spherically symmetric solutions to the Jordan-Brans-Dicke field equations under the assumption that the space-time may possess an arbitrary number of spatial dimensions. Assuming a perfect fluid with the equation of state p = ερ, we show that there are static interior nontrivial solutions in three dimensional Jordan-Brans-Dicke gravity theory.

In the Brans-Dicke model we treat the scalar field exactly and expand the gravitational field in a power series. A comparison with 2D sigma models and φ perturbation theory in four dimensions suggests that the perturbation series in 4D Brans-Dicke model is renormalizable.