scholarly journals Cosmological Models with Big Rip and Pseudo Rip Scenarios in Extended Theory of Gravity

2021 ◽  
pp. 2100086
Author(s):  
Pratik P Ray ◽  
Sankarsan Tarai ◽  
B. Mishra ◽  
S. K. Tripathy
Keyword(s):  
Cosmological Models ◽  
Extended Theory ◽  
Big Rip ◽  
Theory Of Gravity

scholarly journals Rip cosmologies, wormhole solutions and big trip in the f(T,𝒯 ) theory of gravity

2020 ◽  
Vol 17 (08) ◽  
pp. 2050116 ◽  
Author(s):  
Maxime Z. Arouko ◽  
Ines G. Salako ◽  
A. D. Kanfon ◽  
M. J. S. Houndjo ◽  
Etienne Baffou
Keyword(s):  
Energy Momentum Tensor ◽  
Late Phase ◽  
Momentum Tensor ◽  
Cosmological Models ◽  
The Other ◽  
Throat Radius ◽  
Eos Parameter ◽  
Wormhole Throat ◽  
Initial Epoch ◽  
Theory Of Gravity

Rip cosmological models have been investigated in the framework of [Formula: see text] theory of gravity, where [Formula: see text] denotes the torsion and [Formula: see text] is the trace of the energy–momentum tensor. These phantom cosmological models revealed that at initial epoch a EoS parameter [Formula: see text] tends asymptotically at late phase to [Formula: see text] [Formula: see text]. On the other hand, Wormhole Solutions and Big Trip have been subject to an investigation. The wormhole throat radius [Formula: see text] and the conditions to be satisfied to produce the Big Trip phenomenon have been discussed.

scholarly journals Investigating $f(R)$ gravity and cosmologies

2021 ◽  
Author(s):  
Vaibhav Kalvakota
Keyword(s):  
General Relativity ◽  
Lagrangian Density ◽  
Ricci Scalar ◽  
Metric Tensor ◽  
Extended Theory ◽  
Theories Of Gravity ◽  
Theory Of Gravity ◽  
Hilbert Action ◽  
Geometric Nature

The f (R) theory of gravity is an extended theory of gravity that is based on general relativity in the simplest case of $f(R) = R$. This theory extends such a function of the Ricci scalar into arbitrary functions that are not necessarily linear, i.e. could be of the form $f(R) = \alpha R^{2}$. The action for such a theory would be $S_{EH} = \frac{1}{2k} \int f(R) + L^{m}\; d^{4}x\sqrt{−g}$, where $S_{EH}$ is the Einstein-Hilbert action for our theory, $g$ is the determinant of the metric tensor $g_{\mu \nu}$ and $L^{m}$ is the Lagrangian density for matter. In this paper, we will look at some of the physical implications of such a theory, and the importance of such a theory in cosmology and in understanding the geometric nature of such f (R) theories of gravity.

scholarly journals Charged wormholes in f(R,T)-extended theory of gravity

2019 ◽  
Vol 28 (08) ◽  
pp. 1950098 ◽  
Author(s):  
P. H. R. S. Moraes ◽  
W. de Paula ◽  
R. A. C. Correa
Keyword(s):  
Degrees Of Freedom ◽  
Matter Content ◽  
Nonlinear Electrodynamics ◽  
Energy Conditions ◽  
Field Equations ◽  
Extended Theory ◽  
Extended Theories Of Gravity ◽  
Theories Of Gravity ◽  
Theory Of Gravity ◽  
Physical Quantities

Wormholes (WHs) are a solution for General Relativity field equations which characterize a passage or tunnel that connects two different regions of spacetime and is filled by some sort of exotic matter that does not satisfy the energy conditions. On the other hand, it is known that in extended theories of gravity, the extra degrees of freedom once provided may allow the energy conditions to be obeyed and, consequently, the matter content of the WH to be nonexotic. In this work, we obtain, as a novelty in the literature, solutions for charged WHs in the [Formula: see text]-extended theory of gravity. We show that the presence of charge in these objects may be a possibility to respect some stability conditions for their metric. Also, remarkably, the energy conditions are respected in the present approach. In addition, we argue that our framework can be very useful to study the possibility of evolving [Formula: see text] and [Formula: see text]-dimensional WH spacetime within the context of nonlinear electrodynamics, which open a new window to probe the physical quantities in a WH-type solution.

Sign in / Sign up

Export Citation Format

Share Document