Quintessential phenomena in higher-dimensional space-time

Abstract

The higher dimensional cosmology provides a natural setting to treat, at a classical level, the cosmological effects of vacuum energy. Here we discuss two situations where starting with an ordinary matter field without any equation of state we end up with a Chaplygin type of gas apparently as a consequence of extra dimensions. In the second case we study the quintessential phenomena in higher dimensional spacetime with the help of a Chaplygin type of matter field. The first case suffers from the disqualification that no dimensional reduction occurs, which is, however, rectified in the second case. Both the models show the sought after feature of occurrence of \emph{flip} in the rate of expansion. It is observed that with the increase of dimensions the occurrence of \emph{flip} is delayed for both the models, more in line with current observational demands. Interestingly we see that depending on some initial conditions our model admits QCDM, $\Lambda$CDM and also Phantom like evolution within a unified framework. Our solutions are general in nature in the sense that when the extra dimensions are switched off the known 4D model is recovered.