Constraints from Compact Star Observations on Non-Newtonian Gravity in Strange Stars Based on a Density Dependent Quark Mass Model

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 J0740 + 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 MeV, m(d0) = 4.67 MeV, and m(s0) = 93 MeV, we find that a strange star can exist for values of the non-Newtonian gravity parameter g(2)/mu(2) in the range of 4.58 GeV-2 <= g(2) /mu(2) <= 9.32 GeV-2, and that the parameters D and C of the QMDD model arc restricted to 158.3 MeV <= D-1/2 <= 181.2 MeV and -0.65 <= C <= -0.12. It is found that the largest possible maximum mass of a strange star obtained with the QMDD model is 2.42 M-circle dot and that the secondary component of GW190814 with a mass of 2.59(-0.09)(+0.08) M-circle dot could not be a static strange star. We also fmd that for the mass and radius of PSR J0030 + 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 J0740 + 6620, GW170817 and PSR J0030 + 0451 simultaneously. However, for the mass and radius given by Miller et al., no such parameter space exist.