Zobrazeno 1 - 10
of 128
pro vyhledávání: '"TOPORENSKY, ALEXEY"'
Publikováno v:
Gen Relativ Gravit 56, 110 (2024)
We consider dynamics of a scalar field in compactification scenario of Einstein-Gauss-Bonnet cosmology. It is shown that if the field is non-minimally coupled to curvature, its asymptotic value under certain conditions may be shifted from the minimum
Externí odkaz:
http://arxiv.org/abs/2407.20409
Publikováno v:
JCAP 09 (2024) 050
We propose new slow-roll approximations for inflationary models with the Gauss-Bonnet term. We find more accurate expressions of the standard slow-roll parameters as functions of the scalar field. To check the accuracy of approximations considered we
Externí odkaz:
http://arxiv.org/abs/2403.06147
Autor:
Müller, Daniel, Toporensky, Alexey
We have found numerically initial conditions in the $(R, H)$ plane leading to a successful Starobinsky inflation in $R+R^2$ gravity for a isotropic metrics with positive spatial curvature. Trajectories can reach inflation regime either directly or go
Externí odkaz:
http://arxiv.org/abs/2310.15377
Autor:
Chirkov, Dmitry, Toporensky, Alexey
It is known that spatial curvature can stabilize extra dimensions in Lovelock gravity. In the present paper we study stability of the stabilization solutions in 3-d order Lovelock gravity. We show that in the case of negative spatial curvature of ext
Externí odkaz:
http://arxiv.org/abs/2301.07192
Publikováno v:
Int.J.Geom.Meth.Mod.Phys. 19 (2022) 10, 2250147
In this paper we generalize our previous results on spin connection for the linear scalar cosmological perturbation in $f(T)$ theory to wider class of theories which includes a scalar field $\Phi$ non-minimally coupled to torsion, and allows $\Phi$-d
Externí odkaz:
http://arxiv.org/abs/2110.12332
Autor:
Muller, Daniel, Toporensky, Alexey
Publikováno v:
Gen.Rel.Grav. 53 (2021) 6, 60
We consider conditions for existence and stability of a static cosmological solution in quadratic gravity. It appears that such a solution for a Universe filled by only one type of perfect fluid is possible in a wide range of the equation of state pa
Externí odkaz:
http://arxiv.org/abs/2104.13460
Autor:
Järv, Laur, Toporensky, Alexey
Publikováno v:
Eur. Phys. J. C 82, 179 (2022)
We reconsider the dynamical systems approach to analyze inflationary universe in the Jordan frame models of scalar field nonminimally coupled to curvature. The adopted set of variables allows us to clearly distinguish between different asymptotic sta
Externí odkaz:
http://arxiv.org/abs/2104.10183
Publikováno v:
Eur. Phys. J. C 81, 136 (2021)
In this paper we perform systematic investigation of all possible solutions with static compact extra dimensions and expanding three-dimensional subspace (``our Universe''). Unlike previous papers, we consider extra-dimensional subspace to be constan
Externí odkaz:
http://arxiv.org/abs/2012.03517
Publikováno v:
Eur. Phys. J. C 80 (2020) no. 11, 1054
We consider certain aspects of cosmological dynamics of a spatially curved Universe in $f(T)$ gravity. Local analysis allows us to find conditions for bounces and for static solutions; these conditions appear to be in general less restrictive than in
Externí odkaz:
http://arxiv.org/abs/2009.11410
Autor:
Pozdeeva, Ekaterina O., Gangopadhyay, Mayukh Raj, Sami, Mohammad, Toporensky, Alexey V., Vernov, Sergey Yu.
Publikováno v:
Phys. Rev. D 102, 043525 (2020)
We investigate inflationary dynamics in the framework of the Einstein-Gauss-Bonnet gravity. In the model under consideration, the inflaton field is non-minimally coupled to the Gauss-Bonnet curvature invariant, so that the latter appears to be dynami
Externí odkaz:
http://arxiv.org/abs/2006.08027