Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 53, p.32-37 (2016)

Formation of the spherical voids in the models of the universe with dark energy

M. Tsizh, postgrad. stud.,
B. Novosyadlyj, Dr. Sci., prof.
Ivan Franko National University of Lviv, Lviv

Abstract
We analyze evolution of cosmological perturbations which lead to the formation of large voids in the distribution of galaxies. We suppose that perturbations are spherical and main energetic components – radiation, matter and dark energy – are continuous media with ideal fluid energy-momentum tensors, which interact only gravitationally. Equations of the evolution of perturbations in the comoving to cosmological background reference frame for every component are obtained from equations of conservation and Einstein’s ones and are integrated by modified Euler method with setting the initial conditions at the early stage of evolution in radiation-dominated epoch, when the scale of perturbation is mush larger than particle horizon. Obtained results illustrate dynamics of dark energy in the void region and its dependence on parameter of effective speed of sound of dark energy.

Keywords
dynamical dark energy, cosmic voids, cosmological perturbations.

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http://www.cs.toronto.edu/NA/dverk.f.gz

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