### Abstract

We study a specific model of anisotropic strange stars in the modified f (R, T )-type gravity by deriving solutions to the modified Einstein field equations representing a spherically symmetric anisotropic stellar object. We take a standard assumption that f(R, T ) = R + 2χT , where R is Ricci scalar, T is the trace of the energy-momentum tensor of matter, and χ is a coupling constant. To obtain our solution to the modified Einstein equations, we successfully apply the 'embedding class one' techniques. We also consider the case when the strange quark matter (SQM) distribution is governed by the simplified MIT bag model equation of state given by p_{r} = ^{1}_{3} (ρ − 4B), where B is bag constant. We calculate the radius of the strange star candidates by directly solving the modified TOV equation with the observed values of the mass and some parametric values of B and χ. The physical acceptability of our solutions is verified by performing several physical tests. Interestingly, besides the SQM, another type of matter distribution originates due to the effect of coupling between the matter and curvature terms in the f (R, T ) gravity theory. Our study shows that with decreasing the value of χ, the stellar systems under investigations become gradually massive and larger in size, turning them into less dense compact objects. It also reveals that for χ < 0 the f (R, T ) gravity emerges as a suitable theory for explaining the observed massive stellar objects like massive pulsars, super-Chandrasekhar stars, and magnetars, etc., which remain obscure in the standard framework of General Relativity.

Original language | English |
---|---|

Pages (from-to) | 5652-5665 |

Number of pages | 14 |

Journal | Monthly Notices of the Royal Astronomical Society |

Volume | 485 |

Issue number | 4 |

DOIs | |

Publication status | Published - 13 Mar 2019 |

### Fingerprint

### Keywords

- Black hole physics
- Gravitation
- Hydrodynamics
- Methods: analytical
- Pulsars: general
- Stars: neutron

### ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science

### Cite this

*Monthly Notices of the Royal Astronomical Society*,

*485*(4), 5652-5665. https://doi.org/10.1093/mnras/stz708

**Exploring physical features of anisotropic strange stars beyond standard maximum mass limit in f (R, T ) gravity.** / Deb, Debabrata; Ketov, Sergei V.; Maurya, S. K.; Khlopov, Maxim; Moraes, P. H.R.S.; Ray, Saibal.

Research output: Contribution to journal › Article

*Monthly Notices of the Royal Astronomical Society*, vol. 485, no. 4, pp. 5652-5665. https://doi.org/10.1093/mnras/stz708

}

TY - JOUR

T1 - Exploring physical features of anisotropic strange stars beyond standard maximum mass limit in f (R, T ) gravity

AU - Deb, Debabrata

AU - Ketov, Sergei V.

AU - Maurya, S. K.

AU - Khlopov, Maxim

AU - Moraes, P. H.R.S.

AU - Ray, Saibal

PY - 2019/3/13

Y1 - 2019/3/13

N2 - We study a specific model of anisotropic strange stars in the modified f (R, T )-type gravity by deriving solutions to the modified Einstein field equations representing a spherically symmetric anisotropic stellar object. We take a standard assumption that f(R, T ) = R + 2χT , where R is Ricci scalar, T is the trace of the energy-momentum tensor of matter, and χ is a coupling constant. To obtain our solution to the modified Einstein equations, we successfully apply the 'embedding class one' techniques. We also consider the case when the strange quark matter (SQM) distribution is governed by the simplified MIT bag model equation of state given by pr = 13 (ρ − 4B), where B is bag constant. We calculate the radius of the strange star candidates by directly solving the modified TOV equation with the observed values of the mass and some parametric values of B and χ. The physical acceptability of our solutions is verified by performing several physical tests. Interestingly, besides the SQM, another type of matter distribution originates due to the effect of coupling between the matter and curvature terms in the f (R, T ) gravity theory. Our study shows that with decreasing the value of χ, the stellar systems under investigations become gradually massive and larger in size, turning them into less dense compact objects. It also reveals that for χ < 0 the f (R, T ) gravity emerges as a suitable theory for explaining the observed massive stellar objects like massive pulsars, super-Chandrasekhar stars, and magnetars, etc., which remain obscure in the standard framework of General Relativity.

AB - We study a specific model of anisotropic strange stars in the modified f (R, T )-type gravity by deriving solutions to the modified Einstein field equations representing a spherically symmetric anisotropic stellar object. We take a standard assumption that f(R, T ) = R + 2χT , where R is Ricci scalar, T is the trace of the energy-momentum tensor of matter, and χ is a coupling constant. To obtain our solution to the modified Einstein equations, we successfully apply the 'embedding class one' techniques. We also consider the case when the strange quark matter (SQM) distribution is governed by the simplified MIT bag model equation of state given by pr = 13 (ρ − 4B), where B is bag constant. We calculate the radius of the strange star candidates by directly solving the modified TOV equation with the observed values of the mass and some parametric values of B and χ. The physical acceptability of our solutions is verified by performing several physical tests. Interestingly, besides the SQM, another type of matter distribution originates due to the effect of coupling between the matter and curvature terms in the f (R, T ) gravity theory. Our study shows that with decreasing the value of χ, the stellar systems under investigations become gradually massive and larger in size, turning them into less dense compact objects. It also reveals that for χ < 0 the f (R, T ) gravity emerges as a suitable theory for explaining the observed massive stellar objects like massive pulsars, super-Chandrasekhar stars, and magnetars, etc., which remain obscure in the standard framework of General Relativity.

KW - Black hole physics

KW - Gravitation

KW - Hydrodynamics

KW - Methods: analytical

KW - Pulsars: general

KW - Stars: neutron

UR - http://www.scopus.com/inward/record.url?scp=85066936671&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85066936671&partnerID=8YFLogxK

U2 - 10.1093/mnras/stz708

DO - 10.1093/mnras/stz708

M3 - Article

VL - 485

SP - 5652

EP - 5665

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -