Non-Newtonian Gravity in Strange Quark Stars and Constraints from the Observations of PSR J0740+6620 and GW170817

Abstract

We investigate the effects of non-Newtonian gravity on the properties of strange quark stars (QSs) and constrain the parameters of the standard MIT bag model used to describe strange quark matter (SQM) by employing the mass of PSR J0740+6620 and the tidal deformability of GW170817. We find that, for the standard MIT bag model, these mass and tidal deformability observations would rule out the existence of QSs if non-Newtonian gravity effects are ignored. For a strange quark mass of m s = 95 MeV, we find that QSs can exist for values of the non-Newtonian gravity parameter g 2/μ 2 in the range of 1.37 GeV−2 ≤ g 2/μ 2 ≤ 7.28 GeV−2 and limits on the bag constant and the strong interaction coupling constant of the SQM model given by 141.3 MeV ≤ B 1/4 ≤ 150.9 MeV and α S ≤ 0.56. For a strange quark mass of m s = 150 MeV, QSs can exist for 1.88 GeV−2 ≤ g 2/μ 2 ≤ 6.27 GeV−2 and limits on the parameters of the SQM model given by 139.7 MeV ≤ B 1/4 ≤ 147.3 MeV and α S ≤ 0.49.

Strange stars with a mirror-dark-matter core confronting with the observations of compact stars

“…We investigate the allowed parameter space of the standard MIT bag model according to the following five constraints [e.g., 11,12,60,61,62,63]:…”

“…Following Yang et al [11], we briefly review the phenomenological model for the EOS employed in this paper, namely, the standard bag model [5,6,7,10]. In that model, u and d quarks are treated as massless particles but s quarks have a finite mass, m s .…”

“…The thermodynamic potential for the u, d and s quarks, and for the electrons (Ω i with i = u, d, s, e) are the same as Refs. [6,11] with the renomormalization constant σ = 300 MeV, and the current mass of s quark is taken as m s = 93 MeV [41]. The number density of each species is given by…”

“…Yang et al [11,12] found that both for the standard MIT bag model and for the density dependent quark mass model, the existence of SSs is ruled out by the mass of PSR J0740+6620 (2.14 +0.10 −0.09 M ⊙ for a 68.3% credibility interval; 2.14 +0.20 −0.18 M ⊙ for a 95.4% credibility interval) [13] and the dimensionless tidal deformability of a 1.4 M ⊙ star of GW170817 (Λ(1.4) = 190 +390 −120 ) [14,15]. However, Yang et al [11,12] demonstrated that if non-Newtonian gravity effects are considered, SSs can exist for certain ranges of the values of the non-Newtonian gravity parameter. In this Letter, instead of employing the non-Newtonian gravity effects, we propose an alternative explanation to the above mentioned astrophysical observations which supposes that SSs have a mirror-dark-matter (MDM) core.…”

Constraints on Theoretical Predictions beyond the Standard Model from the Casimir Effect and Some Other Tabletop Physics

“…It should be noted that although the Yukawa-type corrections to the Newton gravitational law are short-ranged, they are important not only in the tabletop laboratory experiments but in astrophysics as well. For instance, as shown in [86], these corrections make an impact on the properties of quark stars and should be taken into account for interpretation of observations related to some specific events and objects.…”