We want to study the perturbation growth of an initial seed of an ellipsoidal shape in Top-Hat collapse model of the structure formation in the Modied Chaplygin gas cosmology. Considering reasonable values of the constants and the parameters of the model under study, we can show that a very small deviation from spherical symmetry (ellipsoidal geometry) in the initial seed leads to a nal highly ...

Nonlinear growth of one-dimensional density structures with a frozen-in magnetic field is investigated in Newtonian cosmology. A mechanism of magnetic field amplification is discussed. We discuss the relation between the initial conditions for the velocity field and the basic time-scales determining the growth of the magnetized structure.

Distributional sources of cosmic walls crossed by cosmic strings from Riemann-Cartan (RC) Geometry. The matter density of the planar wall is maximum at the point where the cosmic string crosses the cosmic wall. Cartan torsion is has a support on the cosmic string given by the Dirac δ-function. Off the sources are left with a torsionless vacuum. PACS number(s) : 0420,0450,1127 Departamento de F́ı...

We present a new concept, the Spine of the Cosmic Web, for the topological analysis of the Cosmic Web and the identification of its filaments and walls. Based on the watershed segmentation of the cosmic density field, the method invokes the local properties of the regions adjacent to the critical points, which define its separatrices. Our method allows their classification into walls and the sp...

An example is given of a plane topological torsion defect representing a cosmic wall double wall in teleparallel gravity.The parallel planar walls undergone a repulsive gravitational force due to Cartan torsion.This is the first example of a non-Riemannian double cosmic wall.It is shown that the walls oscillate with a speed that depends on torsion and on the surface density of the wall.Cartan t...

Let us start our considerations here from the cosmic era of baryonelectron (or proton-electron) recombination. In standard cosmology it is usually assumed that at the cosmic recombination era photons and matter, meaning electrons and protons, in this phase of the cosmic evolution, are dynamically and physically tightly bound to each other and undergo strong mutual interactions via Coulomb colli...

A relativistic generalisation of a well-known method for approximating the dynamics of topological defects in condensed matter is constructed, and applied to the evolution of domain walls in a cosmological context. It is shown that there are self-similar “scaling” solutions, for which one can in principle calculate many quantities of interest without recourse to numerical simulations. Here, the...