Zobrazeno 1 - 10
of 56
pro vyhledávání: '"Tretyakov, Petr"'
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:
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:
Tretyakov, Petr V.
Publikováno v:
MPLA V.37, No. 08, 2250046 (2022)
In the present paper we discuss dynamic of anisotropic Bianchi I Universe filled by the perfect fluid in teleparallel $f(T)$-gravity. By using as analytical as numerical approaches we confirm the main results of previous authors such as presence of f
Externí odkaz:
http://arxiv.org/abs/2109.14457
Autor:
Tretyakov, Petr V.
Publikováno v:
Eur. Phys. J. C, 78 11 (2018) 896
In present paper we propose further modification of $f(R,T)$-gravity (where $T$ is trace of energy-momentum tensor) by introducing higher derivatives matter fields. We discuss stability conditions in proposed theory and find restrictions for paramete
Externí odkaz:
http://arxiv.org/abs/1810.11313
We study in detail the phase space of a Friedmann-Robertson-Walker Universe filled with various cosmological fluids which may or may not interact. We use various expressions for the equation of state, and we analyze the physical significance of the r
Externí odkaz:
http://arxiv.org/abs/1707.08661
In this paper we study the occurrence of accelerating universe versus decelerating universe between the F(R) gravity frame (Jordan frame) and non-minimally coupled scalar field theory frame, and the minimally coupled scalar field theory frame (Einste
Externí odkaz:
http://arxiv.org/abs/1701.02381
Autor:
Tretyakov, Petr V.
We discuss possible instabilities in higher-derivative matter fields theories. These theories has two free parameters $\beta_1$ and $\beta_4$. By using dynamical system approach we explicitly demonstrate that for stability of Minkowski space in expan
Externí odkaz:
http://arxiv.org/abs/1608.05281
Autor:
Tretyakov, Petr V.
Publikováno v:
Mod. Phys. Lett. A, Vol. 31, No. 14 (2016) 1650085
We discuss modified teleparallel gravity with function $f(T,T_G)$ in the action, where function depend on two arguments: torsion scalar $T$ and analogue of Gauss-Bonnet invariant $T_G$. In contradistinction to usual teleparallel gravity $f(T)$, this
Externí odkaz:
http://arxiv.org/abs/1602.01287
We explore inflationary cosmology in a theory where there are two scalar fields which non-minimally couple to the Ricci scalar and an additional $R^2$ term, which breaks the conformal invariance. Particularly, we investigate the slow-roll inflation i
Externí odkaz:
http://arxiv.org/abs/1505.00854
Autor:
Tretyakov, Petr V.
Publikováno v:
Int. J. Geom. Methods Mod. Phys., 12, 1550094 (2015)
We discuss the Minkowski stability problem in modified gravity by using dynamical system approach. The method to investigate dynamical stability of Minkowski space was proposed. This method was applied for some modified gravity theories, such as $f(R
Externí odkaz:
http://arxiv.org/abs/1407.3980