We calculate the temperature and polarization patterns generated in anisotropic cosmological models drawn from the Bianchi classification. We show that localized features in the temperature pattern, perhaps similar to the cold spot observed in the Wilkinson Microwave Anisotropy Probe (WMAP) data, can be generated in models with negative spatial curvature, i.e. Bianchi types V and VIIh. Both the...

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmological string is investigated. A nonlinear spinor field is used to simulate the cosmic string. It is shown that the spinor field simulation allows one to solve the corresponding system of Einstein’s equation without any additional assumptions. Pacs: 95.30.Sf; 98.80.Jk; 04.20.Ha

We investigate the dynamics of spatially homogeneous solutions of the EinsteinVlasov equations with Bianchi type I symmetry by using dynamical systems methods. All models are forever expanding and isotropize toward the future; toward the past there exists a singularity. We identify and describe all possible past asymptotic states; in particular, on the past attractor set we establish the existe...

Presented are exactly integrable models with pure radiation in R2 gravity a cosmological constant related to wave-like Shapovalov spacetimes type II. Spatially homogeneous of were considered. The obtained solutions belong spaces III according the Bianchi classification and N Petrov classification. For under consideration, exact for equations motion test particles Hamilton–Jacobi formalism. mode...

We study the low energy string effective action with an exponential type dilaton potential and vanishing torsion in a Bianchi type I space-time geometry. In the Einstein and string frames the general solution of the gravitational field equations can be expressed in an exact parametric form. Depending on the values of the dilaton coupling constant and of the coefficient in the exponential, the o...

Spatially homogeneous cosmological models reduce to Hamiltonian systems in a low dimensional Minkowskian space moving on the total energy shellH = 0. Close to the initial singularity some models (those of Bianchi type VIII and IX) can be reduced further, in a certain approximation, to a non-compact triangular billiard on a 2-dimensional space of constant negative curvature with a separately con...

In this work we present cosmological quantum solutions for all Bianchi Class A cosmological models obtained by means of supersymmetric quantum mechanics . We are able to write one general expression for all bosonic components occuring in the Grassmann expansion of the wave function of the Universe for this class of models. These solutions are obtained by means of a more general ansatz for the s...

In this work it is shown that there are some spatially homogeneous but anisotropic models (Kantowski-Sachs and Bianchi type-III), with a positive cosmological constant, for which the inhomogeneities in the distribution of matter on the surface of the last scattering produce anisotropies (in large angular scales θ ∼ > 10 ◦) that do not differ from the ones produced in Friedmann-Lemâıtre-Robertso...