Non-Newtonian gravity in strange stars and constraints from the observations of compact stars

Abstract

We study non-Newtonian gravity effects on the structure and the tidal deformability of strange stars using the standard MIT model, and compare the theory with the observations of compact stars following the approach of Yang et al. (2020). Different to Yang et al. (2020), in which the authors only employed the constraints from the mass of PSR J0740+6620 and the dimensionless tidal deformability of a 1.4M⊙ star of GW170817, here we also consider another constraint, namely, from the observations of the mass and radius of the isolated pulsar PSR J0030+0451 by NICER. We find that for the standard MIT model, strange stars can not agree with the observations of PSR J0740+6620, PSR J0030+0451 and GW170817 simultaneously. In other words, for the standard MIT model, the observations of PSR J0740+6620, PSR J0030+0451 and GW170817 rule out the possibility of the existence of strange stars even when we consider the effects of non-Newtonian gravity.