BULK VISCOUS BIANCHI TYPE I BAROTROPIC FLUID COSMOLOGICAL MODEL WITH VARYING Λ AND FUNCTIONAL RELATION ON HUBBLE PARAMETER IN ROSEN’S BIMETRIC GRAVITY

We have deduced that bulk viscous Bianchi type I barotropic fluid cosmological model with varying $\Lambda$ and functional relation on hubble parameter by solving the field equations bimetric theory of gravitation. It is observed that our model has exponentially accelerating expansion at late time starting with decelerating expansion which agreed the observation of Perlmutter (1998), Knop (2003), Tegmark (2004) and Spergel (2006). In the beginning, our model has more than three spatial-dimensions then it switched over to three-dimensional spatial geometry at late epoch of time and it is agreed with Borkar et al. (2013). Other geometrical and physical behavior of the model have been studied.

Towards the signs of new physics through the spectral action

We review recent results obtained by using the spectral action applied to some simple physical models built in the noncommutative geometry framework. The first result, based on the generalization of the spectral action principle to the case of the fermionic action leads to the lowest order corrections that can possibly explain the huge difference between the electron and neutrino masses. In the second case, the extension of the family of Dirac operators for the product of finite geometry with the Riemannian manifold but without a product metric leads to a theory with two metrics that is similar to the models of bimetric gravity.

Cosmology of Bigravity

This article discusses cosmology, bimetric gravity and their possible interplay.