Erratum: Cosmological models in energy-momentum-squared gravity [Phys. Rev. D 
<b>96</b>
, 123517 (2017)]

Board, Charles V. R.; Barrow, John D.

doi:10.1103/physrevd.98.129902

Cited by 26 publications

(35 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further, they argued that the "repulsive" nature of the cosmological constant plays a significant role at early times for resolving the singularity only after matter-dominated era. Board and Barrow [12] investigated the range of exact solutions for isotropic spacetime, presence of singularities, cosmic accelerated expansion as well as evolution with a particular model of this theory. Morares and Sahoo [13] studied non-exotic matter wormholes while Akarsu et al [14] explored possible constraints from neutron stars in this framework.…”

Section: Introductionmentioning

confidence: 99%

Noether symmetry approach in energy-momentum squared gravity

Sharif

Gul

2020

Phys. Scr.

View full text Add to dashboard Cite

In this paper, we investigate the newly developed f (R, T 2 ) theory (R is the Ricci scalar and T 2 = T αβ T αβ , T αβ demonstrates the energymomentum tensor) to explore some viable cosmological models. For this purpose, we use the Noether symmetry approach in the context of flat Friedmann-Robertson-Walker (FRW) universe. We solve the Noether equations of this modified theory for two types of models and obtain the symmetry generators as well as corresponding conserved quantities. We also evaluate exact solutions and investigate their physical behavior via different cosmological parameters. For the prospective models, the graphical behavior of these parameters indicate consistency with recent observations representing accelerated expansion of the universe. In the first case, we take a special model of this theory and obtain new class of exact solutions with the help of conserved quantities. Secondly, we consider minimal and non-minimal coupling models of f (R, T 2 ) gravity. We conclude that conserved quantities are very useful to derive the exact solutions that are used to study the cosmic accelerated expansion.

show abstract

Section: Introductionmentioning

confidence: 99%

Noether symmetry approach in energy-momentum squared gravity

Sharif

Gul

2020

Phys. Scr.

View full text Add to dashboard Cite

show abstract

“…For a detailed study of the model and its cosmological consequences, we refer the reader to [9]. In [10] a general version of EMSG has been investigated and several interesting exact cosmological solutions have been found.…”

Section: Introductionmentioning

confidence: 99%

Compact stars in energy-momentum squared gravity

2018

View full text Add to dashboard Cite

A simple generalization to Einstein's general relativity (GR) was recently proposed which allows a correction term T αβ T αβ in the action functional of the theory. This theory is called Energy-Momentum Squared Gravity (EMSG) and introduces a new coupling parameter η. EMSG resolves the big bang singularity and has a viable sequence of cosmological epochs in its thermal history. Interestingly, in the vacuum EMSG is equivalent to GR, and its effects appear only inside the matterenergy distribution. More specifically, its consequences appear in high curvature regime. Therefore it is natural to expect deviations form GR inside compact stars. In order to study spherically symmetric compact stars in EMSG, we find the relativistic governing equations. More specifically, we find the generalized version of the Tolman-Oppenheimer-Volkov equation in EMSG. Finally we present two analytical solutions, and two numerical solutions for the field equations. For obtaining the numerical solutions we use polytropic equation of state which is widely used to understand the internal structure of neutron stars in the literature. Eventually we find a mass-radius relation for neutron stars. Also, We found that EMSG, depending on the central pressure of the star and the magnitude of free parameter η, can lead to larger or smaller masses for neutron stars compared with GR. Existence of high-mass neutron stars with ordinary polytropic equation of state in EMSG is important in the sense that these stars exist in GR when equation of state is more complicated.

show abstract

“…if we ignore the angular momentum in the system, i.e., κ = 0, then the well-known dispersion relation already derived in Jeans analysis of an infinite medium is recovered, see Eq. (55). If the combination of the last two terms in the right hand side of (102) gets positive, or equivalently if β ≥ 1, the all the wavelengths will be stable.…”

Section: The Dispersion Relation and The Toomre's Parametermentioning

confidence: 99%

“…On the other hand, the tensor θ µν is defined as the variation of Q with respect to the metric tensor, namely θ µν = δQ/δg µν . For a perfect fluid the energy-momentum tensor and θ µν are written as follows (for more details see [55,56])…”

Section: Field Equations Of Emsgmentioning

confidence: 99%

Jeans analysis in energy–momentum-squared gravity

et al. 2020

View full text Add to dashboard Cite

In this paper, we study the Jeans analysis in the context of energy-momentum-squared gravity (EMSG). More specifically we find the new Jeans mass for non-rotating infinite mediums as the smallest mass scale for local perturbations that can be stable against its own gravity. Furthermore, for rotating mediums, specifically for rotating thin disks in the context of EMSG, we find a new Toomre-like criterion for the local gravitational stability. Finally, the results are applied to a hyper-massive neutron star, as an astrophysical system. Using a simplified toy model we have shown that, for a positive (negative) value of the EMSG parameter α, the system is stable (unstable) in a wide range of α. On the other hand, no observational evidence has been reported on the existence of local fragmentation in HMNS. Naturally, this means that EMSG with positive α is more acceptable from the physical point of view.

show abstract

Erratum: Cosmological models in energy-momentum-squared gravity [Phys. Rev. D 96 , 123517 (2017)]

Cited by 26 publications

References 0 publications

Noether symmetry approach in energy-momentum squared gravity

Noether symmetry approach in energy-momentum squared gravity

Compact stars in energy-momentum squared gravity

Jeans analysis in energy–momentum-squared gravity

Contact Info

Product

Resources

About