arXiv subjects

K. K. Yerzhanov

Publications and source records attributed to K. K. Yerzhanov.

5 recordsLinked to original sources

arXiv2012

Some Models of Cyclic and Knot Universes

In this paper, we obtained a class of oscillatory, cyclic and knot type solutions from the non-linear Friedmann equations. This is performed by choosing specific forms of energy density and pressure of matter. All the expressions written here are in dimensionless form. We show that evolutionary path taken by the spatial coordinates in the model follow various knots, specifically trefoil and eight-knots. We provide several examples and plot relevant cosmological parameters in figures. Our cyclic models can be interpreted as a periodic cosmological model, such that early and late time acceleration are unified under the same mechanism.

physics.gen-ph↗

arXiv2011

Pure kinetic k-essence as the cosmic speed-up

In this paper, we consider three types of k-essence. These k-essence models were presented in the parametric forms. The exact analytical solutions of the corresponding equations of motion are found. It is shown that these k-essence models for the presented solutions can give rise to cosmic acceleration.

astro-ph.CO↗

arXiv2010

Accelerated expansion of the Universe driven by G-essence

In the present work we analyze the g-essence model for the particular Lagrangian: $L=R+2[αX^n+εY-V(ψ,\barψ)]$. The g-essence models were proposed recently as an alternative and as a generalization to the scalar k-essence. We have presented the 3 types solutions of the g-essence model. We reconstructed the corresponding potentials and the dynamics of the scalar and fermionic fields according the evolution of the scale factor. The obtained results shows that the g-essence model can describes the decelerated and accelerated expansion phases of the universe.

astro-ph.CO↗

arXiv2010

Accelerating cosmology in F(T) gravity with scalar field

This work deals with $F(T)$ gravity models driven by real scalar fields with usual and phantom dynamics. We illustrate the results with examples of current interest, and we find some analytical solutions for scale factors and scalar fields. The results indicate that torsion-scalar models also admit the accelerated expansion of the universe.

gr-qc↗

arXiv2008

Integrable Isotropic Geometrical Flows and Heisenberg Ferromagnets

Geometrical flows (GF) play an important role in modern mathematics and physics. In this letter we have considered some integrable isotropic GF -- Ricci flows (RF) and mean curvature flows (MCF) -- which are related with integrable Heisenberg ferromagnets. In 2+1 dimensions, these GF have a singularity at $t=t_{0}$.

math.DG↗