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E. G. Vorontsova

Publications and source records attributed to E. G. Vorontsova.

3 recordsLinked to original sources

Parameters of cosmological models and recent astronomical observations

For different gravitational models we consider limitations on their parameters coming from recent observational data for type Ia supernovae, baryon acoustic oscillations, and from 34 data points for the Hubble parameter $H(z)$ depending on redshift. We calculate parameters of 3 models describing accelerated expansion of the universe: the $Λ$CDM model, the model with generalized Chaplygin gas (GCG) and the multidimensional model of I. Pahwa, D.~Choudhury and T.R.~Seshadri. In particular, for the $Λ$CDM model $1σ$ estimates of parameters are: $H_0=70.262\pm0.319$ km\,c${}^{-1}$Mpc${}^{-1}$, $Ω_m=0.276_{-0.008}^{+0.009}$, $Ω_Λ=0.769\pm0.029$, $Ω_k=-0.045\pm0.032$. The GCG model under restriction $α\ge0$ is reduced to the $Λ$CDM model. Predictions of the multidimensional model essentially depend on 3 data points for $H(z)$ with $z\ge2.3$.

gr-qc↗

Black Hole Horizon in Superstring Inspired D-Dimensional Dilaton Gravity

In $D$-dimensional dilaton gravitational model stationary Schwarzschild type solutions (centrally symmetrical solutions in vacuum) are obtained. They contain the two-parameter set of solutions: the first parameter is proportional to a central mass and the second one describes intensity of the dilaton field. If the latter parameter equals zero we have pure Schwarzschild solution with the black hole and constant dilaton field. But when the mentioned parameter is non-zero and the dilaton is non-constant, the black hole horizon vanishes.

hep-th↗