Constraints from compact star observations on non-Newtonian gravity in strange stars based on a density dependent quark mass model
Shu‐Hua Yang, Chun‐Mei Pi, Xiaoping Zheng, Fridolin Weber
Abstract
Using a density dependent quark mass (QMDD) model for strange quark matter, we investigate the effects of non-Newtonian gravity on the properties of strange stars and constrain the parameters of the QMDD model by employing the mass of PSR $\mathrm{J}0740+6620$ and the tidal deformability of GW170817. We find that for the QMDD model these mass and tidal deformability observations would rule out the existence of strange stars if non-Newtonian gravity effects are ignored. For the current quark masses of ${m}_{u0}=2.16\text{ }\text{ }\mathrm{MeV}$, ${m}_{d0}=4.67\text{ }\text{ }\mathrm{MeV}$, and ${m}_{s0}=93\text{ }\text{ }\mathrm{MeV}$, we find that a strange star can exist for values of the non-Newtonian gravity parameter ${g}^{2}/{\ensuremath{\mu}}^{2}$ in the range of $4.58\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}2}\ensuremath{\le}{g}^{2}/{\ensuremath{\mu}}^{2}\ensuremath{\le}9.32\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}2}$, and that the parameters $D$ and $C$ of the QMDD model are restricted to $158.3\text{ }\text{ }\mathrm{MeV}\ensuremath{\le}{D}^{1/2}\ensuremath{\le}181.2\text{ }\text{ }\mathrm{MeV}$ and $\ensuremath{-}0.65\ensuremath{\le}C\ensuremath{\le}\ensuremath{-}0.12$. It is found that the largest possible maximum mass of a strange star obtained with the QMDD model is $2.42\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ and that the secondary component of GW190814 with a mass of ${2.59}_{\ensuremath{-}0.09}^{+0.08}\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ could not be a static strange star. We also find that for the mass and radius of PSR $\mathrm{J}0030+0451$ given by Riley et al. through the analysis of observational data of NICER, there exists a very tiny allowed parameter space for which strange stars computed for the QMDD model agree with the observations of PSR $\mathrm{J}0740+6620$, GW170817 and PSR $\mathrm{J}0030+0451$ simultaneously. However, for the mass and radius given by Miller et al., no such parameter space exist.