This work deals with the violation or retention of symmetries associated self-adjoint extension Hamiltonian for homogeneous but anisotropic Bianchi I cosmological model. is required to make sure quantum evolution unitary. It found that scale invariance lost, Noether are preserved.

Inspired by an interesting counterexample to the cosmic no-hair conjecture found in a supergravity-motivated model recently, we propose multi-field extension, which two scalar fields are allowed non-minimally couple vector fields, respectively. This is shown admit exact Bianchi type I power-law solution. Furthermore, stability analysis based on dynamical system method performed show that this a...

Motivated by the fact that pre-inflationary era may evolve in an exotic way, this work we formalize anisotropic evolution context of modified gravity, focusing on and near vicinity inflationary epochs. We specialize specific metrics like Bianchi Taub theory vacuum F(R) gravity with extra scalar field Gauss-Bonnet gravity. discuss qualitative effects anisotropies Universe also consider several s...

We obtain exact solutions to the field equations for five-dimensional locally rotationally symmetric (LRS) Bianchi type-I spacetime in f(R,T) theory of gravity, where specifically, following three cases are considered: (i) f(R,T)=μ(R+T), (ii) f(R,T)=Rμ+RTμ2, and (iii) f(R,T)=R+μR2+μT, R T, respectively, Ricci scalar trace energy–momentum tensor. It is found that equation state (EOS) parameter w...

A Bianchi type -I metric of Kasner form is considered, when the space is filled with a viscous fluid. Whereas an ideal (nonviscous) fluid permits the Kasner metric to be anisotropic provided that the fluid satisfies the Zel’dovich equation of state, the viscous fluid does not permit the Kasner metric to be anisotropic at all. In the latter case, we calculate the Kasner (isotropic) metric expres...

In this paper we investigate a Bianchi type I transitioning Universe in Brans-Dicke theory. To get an explicit solution of the field equations, assume scalar as $\phi = \phi_{0}\left[t^{\alpha}exp(\beta t)\right]^{\delta}$ with $\phi_{0}$, $\alpha$, $\beta$ and $\delta$ constants. The values $\alpha$ are obtained by probing proposed model recent observational Hubble data (OHD) points. interacti...