Voids in the Cosmic Web as a probe of dark energy [CEA]


The formation of large voids in the Cosmic Web from the initial adiabatic cosmological perturbations of space-time metric, density and velocity of matter is investigated in cosmological model with the dynamical dark energy accelerating expansion of the Universe. It is shown that the negative density perturbations with the initial radius about 50 Mpc in comoving to the cosmological background coordinates and the amplitude corresponding to the r.m.s. temperature fluctuations of the cosmic microwave background lead to the formation of voids with the density contrast up to -0.9, maximal peculiar velocity about 400 km/s and the radius close to the initial one. An important feature of voids formation from the analyzed initial amplitudes and profiles is establishing of the surrounding overdensity shell. We have shown that ratio of the peculiar velocity in units of the Hubble flow to the density contrast in the central part of void does not depend or depends weakly on the distance from center of the void. It is shown also that this ratio is sensitive to the values of dark energy parameters and can be used for finding them on basis of the observational data on mass density and peculiar velocities of galaxies in the voids.

Read this paper on arXiv…

B. Novosyadlyj and M. Tsizh
Thu, 2 Mar 17

Comments: 9 pages, 3 figures; accepted for publication by Condenced Matter Physics