A special Bianchi I universe is constructed in 4D string theory. Geometrically it represents a 3D anti-de-Sitter space crossed with a flat direction whereas in terms of an associated conformal field theory it is an extremal case of a gauged WZWN theory with target the coset SU(1, 1)×R2/R . Some of its properties are discussed. ∗ email: [email protected] † Address after Sep. 1, 1992: Dept. o...

We consider a magnetized degenerate gas of fermions as the matter source of a homogeneous but anisotropic Bianchi I spacetime with a Kasner–like metric. We examine the dynamics of this system by means of a qualitative and numerical study of Einstein-Maxwell field equations which reduce to a non–linear autonomous system. For all initial conditions and combinations of free parameters the gas evol...

Self-consistent solutions to the spinor, scalar and BI gravitational field equations are obtained. The problems of initial singularity and asymptotically isotropization process of the initially anisotropic space-time are studied. It is also shown that the introduction of the Cosmological constant (Λ-term) in the Lagrangian generates oscillations of the BI model, which is not the case in absence...

Some Bianchi type I cosmological models of the universe with time dependent gauge function β for viscous fluid distribution within the framework of Lyra geometry are investigated in which the expansion is considered only in two dimensions i.e. one of the Hubble parameter (H1 = Ȧ A) is zero. To get the deterministic solutions of Einstein’s modified field equations, the viscosity coefficient of b...

The one-loop eeective potential for a massive, quartically self-interacting scalar eld nonminimally coupled to gravity is calculated in a Bianchi I universe with small anisotropy. The kernel of a Schrr odinger-like equation is found, and its coincidence limit used to obtain the determinant of the Klein-Gordon operator. The eeects of the anisotropy on symmetry breaking and the viability of new i...

We make use of a flat, axisymmetric Bianchi I metric to investigate the effects of a magnetic field upon the dynamics of the universe for the previously unconsidered case when the accompanying fluid is a cosmological constant and derive two new solutions to the dynamical equations for this case. We examine the behaviour of the scale factor perpendicular and parallel to the field lines, A(t) and...

As a follow-up of recent article in which we investigated the cosmological background expansion history universe Bianchi type-V models with bulk viscous fluid and evolving Λ Newtonian G parameters, study evolution perturbations current work. In particular, analyse matter over-density that leads to formation large-scale structures Bianchi-V model, compare results standard ΛCDM solutions. Our sug...

We construct phase-space structure of a typical higher-order theory gravity, in the background anisotropic Bianchi-1 mini-superspace, following 'modified Horowitz formalism' as well applying 'Dirac algorithm' (after taking care divergent terms), and establish equivalence. Canonical quantization, semiclassical approximation are performed to expatiate fact that such quantum transits successfully ...