scholarly journals Superpotential method for chiral cosmological models connected with modified gravity

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
S. V. Chervon ◽  
I. V. Fomin ◽  
E. O. Pozdeeva ◽  
M. Sami ◽  
S. Yu. Vernov
Keyword(s):  
Modified Gravity ◽  
Cosmological Models ◽  
Superpotential Method

Anisotropic bulk viscous cosmological models in a modified gravity

2013 ◽  
Vol 350 (1) ◽  
pp. 375-380 ◽  
Author(s):  
D. R. K. Reddy ◽  
R. Bhuvana Vijaya ◽  
T. Vidya Sagar ◽  
R. L. Naidu
Keyword(s):  
Modified Gravity ◽  
Cosmological Models ◽  
Bulk Viscous

scholarly journals Relic gravitational waves in cosmological models based on the modified gravity theories

2021 ◽  
Vol 2081 (1) ◽  
pp. 012002
Author(s):  
I V Fomin ◽  
S V Chervon
Keyword(s):  
Energy Density ◽  
Gravitational Waves ◽  
Modified Gravity ◽  
Direct Detection ◽  
Cosmological Models ◽  
Observational Constraints ◽  
Cosmological Perturbations ◽  
Modified Gravity Theories ◽  
Relic Gravitational Waves ◽  
Gravity Theories

Abstract We consider cosmological models based on the generalized scalar-tensor gravity, which correspond to the observational constraints on the parameters of cosmological perturbations for any model’s parameters. The estimates of the energy density of relic gravitational waves for such a cosmological models were made. The possibility of direct detection of such a gravitational waves using modern and prospective methods was discussed as well.

scholarly journals Superpotential Method for $$F(R)$$ Cosmological Models

2020 ◽  
Vol 51 (4) ◽  
pp. 744-749 ◽  
Author(s):  
S. Yu. Vernov ◽  
V. R. Ivanov ◽  
E. O. Pozdeeva
Keyword(s):  
Cosmological Models ◽  
Superpotential Method

scholarly journals Integrable cosmological models with an additional scalar field

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Vsevolod R. Ivanov ◽  
Sergey Yu. Vernov
Keyword(s):  
Scalar Field ◽  
Cosmological Constant ◽  
Gravity Model ◽  
Modified Gravity ◽  
Field Model ◽  
Cosmic Time ◽  
Cosmological Models ◽  
Conformal Metric ◽  
General Solutions ◽  
Hubble Parameters

AbstractWe consider modified gravity cosmological models that can be transformed into two-field chiral cosmological models by the conformal metric transformation. For the $$R^2$$ R 2 gravity model with an additional scalar field and the corresponding two-field model with the cosmological constant and nonstandard kinetic part of the action, the general solutions have been obtained in the spatially flat FLRW metric. We analyze the correspondence of the cosmic time solutions obtained and different possible evolutions of the Hubble parameters in the Einstein and Jordan frames.

scholarly journals Cosmological models with squared trace in modified gravity

2020 ◽  
Vol 29 (15) ◽  
pp. 2050100
Author(s):  
B. Mishra ◽  
S. K. Tripathy ◽  
Saibal Ray
Keyword(s):  
Modified Gravity ◽  
Hubble Parameter ◽  
Energy Momentum Tensor ◽  
Cosmological Parameters ◽  
Momentum Tensor ◽  
Scale Factor ◽  
Specific Form ◽  
Cosmological Models ◽  
Modified Theory Of Gravity ◽  
Modified Theory

In this work, we present a few simple cosmological models under the modified theory of gravity in the particular form of [Formula: see text], where [Formula: see text] is the Ricci Scalar and [Formula: see text] is the trace of the energy–momentum tensor. Two special cosmological models are studied with (i) hyperbolic scale factor and (ii) specific form of the Hubble parameter. The models are observed to predict relevant cosmological parameters closer to the observational values. Both the models reduce to overlap with the [Formula: see text]CDM model at late times. We have discussed some interesting results related to wormhole solutions as evolved from our model. The possible occurrence of Big Trip in wormholes for the models are also discussed.

scholarly journals Cosmological models in modified gravity theories with extended nonminimal derivative couplings

2017 ◽  
Vol 95 (4) ◽  
Author(s):  
Tiberiu Harko ◽  
Francisco S. N. Lobo ◽  
Emmanuel N. Saridakis ◽  
Minas Tsoukalas
Keyword(s):  
Modified Gravity ◽  
Cosmological Models ◽  
Modified Gravity Theories ◽  
Gravity Theories
Sign in / Sign up

Export Citation Format

Share Document