Tidal deformabilities and radii of strange quark stars
Bolin Li, Yan Yan, Jialun Ping
Abstract
The tidal deformabilities and radii of strange quark stars are studied via the quasiparticle model which includes the nonperturbative features of QCD in the low-density region. The results show that the mass constraint of ${M}_{\mathrm{TOV}}>2.0\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ rules out the EOSs which are soft at low densities, while the constraint on the tidal deformability of ${\mathrm{\ensuremath{\Lambda}}}_{1.4}<800$ from GW170817 rules out the EOSs which are too stiff in the low density region. The range for the radius of a $1.4\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ strange quark star is $11.12\text{ }\text{ }\mathrm{km}<{R}_{1.4}<11.98\text{ }\text{ }\mathrm{km}$. ${\mathrm{\ensuremath{\Lambda}}}_{1.4}$ has a strong correlation with ${R}_{1.4}$, and the empirical correlation function is ${\mathrm{\ensuremath{\Lambda}}}_{1.4}=2.86\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}(R/\mathrm{km}{)}^{6.92}$, which is larger than that for neutron stars. The lower bound of ${\mathrm{\ensuremath{\Lambda}}}_{1.4}>513.66$ is also obtained. $\stackrel{\texttildelow{}}{\mathrm{\ensuremath{\Lambda}}}$ is a monotonically increasing function of the mass ratio $\ensuremath{\eta}$, but the slope is very small. And we conclude that the range of $\stackrel{\texttildelow{}}{\mathrm{\ensuremath{\Lambda}}}$ for GW190425 is $184.81<\stackrel{\texttildelow{}}{\mathrm{\ensuremath{\Lambda}}}<320.08$.