Zobrazeno 1 - 10
of 90
pro vyhledávání: '"Vernov, Sergey Yu."'
Publikováno v:
Phys. Rev. D 110 (2024) 103519
We construct integrable chiral cosmological models with two scalar fields and potentials represented in terms of hyperbolic functions. Using the conformal transformation of the metric and the corresponding models with induced gravity terms, we obtain
Externí odkaz:
http://arxiv.org/abs/2407.12732
Autor:
Kamenshchik, Alexander Y., Pozdeeva, Ekaterina O., Tribolet, Augustin, Tronconi, Alessandro, Venturi, Giovanni, Vernov, Sergey Yu.
The superpotential method is a reconstruction technique which has proven useful to build exact cosmological solutions. We here employ the superpotential method in order to reconstruct the features necessary for the inflaton potential to drive inflati
Externí odkaz:
http://arxiv.org/abs/2406.19762
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
Publikováno v:
SPACE, TIME AND FUNDAMENTAL INTERACTIONS, 2024, V. 1 (46), P. 90
We propose the method for construction of $F(R,\xi)$ gravity model, unifying inflation and primordial black hole formation. The proposed models are based on the Starobinsky $R+R^2$ inflationary model, so, the function $F(R,\xi)$ is a quadratic polyno
Externí odkaz:
http://arxiv.org/abs/2401.12040
Publikováno v:
Phys. Atom. Nuclei 86 (2023) 1526
We study anisotropic solutions for the pure $R^2$ gravity model with a scalar field in the Bianchi I metric. The evolution equations have a singularity at zero value of the Ricci scalar $R$ for anisotropic solutions, whereas these equations are smoot
Externí odkaz:
http://arxiv.org/abs/2301.06836
Publikováno v:
Phys. Scr. 98 (2023) 055001
We propose a one-parametric extension of the Starobinsky $R+R^2$ model by adding the $(R+m^2\beta^2)^{3/2}$ term. The parameter $m$ is the inflaton mass, which is determined in the same way as in the Starobinsky model, and $\beta$ is a dimensionless
Externí odkaz:
http://arxiv.org/abs/2211.10988
Superstring/M-theory is the theory of quantum gravity that can provide the UV-completion to viable inflation models. We modify the Starobinsky inflation model by adding the Bel-Robinson tensor $T^{\mu\nu\lambda\rho}$ squared term proposed as the lead
Externí odkaz:
http://arxiv.org/abs/2211.01546
Publikováno v:
JCAP 03 (2022) 058
We study several extensions of the Starobinsky model of inflation, which obey all observational constraints on the inflationary parameters, by demanding that both the inflaton scalar potential in the Einstein frame and the $F(R)$ gravity function in
Externí odkaz:
http://arxiv.org/abs/2111.09058
Publikováno v:
Eur. Phys. J. C 81 (2021) 985
We consider modified gravity cosmological models that can be transformed into two-field chiral cosmological models by the conformal metric transformation. For the $R^2$ gravity model with an additional scalar field and the corresponding two-field mod
Externí odkaz:
http://arxiv.org/abs/2108.10276
Publikováno v:
Eur. Phys. J. C 81 (2021) 633
Inflationary models with a scalar field nonminimally coupled both with the Ricci scalar and with the Gauss-Bonnet term are studied. We propose the way of generalization of inflationary scenarios with the Gauss-Bonnet term and a scalar field minimally
Externí odkaz:
http://arxiv.org/abs/2104.04995