We study the tidal deformability of bare quark stars and hybrid compact starscomposed of a quark matter core in general relativity, assuming that thedeconfined quark matter exists in a crystalline color superconducting phase. Wefind that taking the elastic property of crystalline quark matter into accountin the calculation of the tidal deformability can break the universal I-Loverelation discovered for fluid compact stars, which connects the moment ofinertia and tidal deformability. Our result suggests that measurements of themoment of inertia and tidal deformability can in principle be used to test theexistence of solid quark stars, despite our ignorance of the high densityequation of state (EOS). Assuming that the moment of inertia can be measured to10% level, one can then distinguish a 1.4 (1) $M_\odot$ solid quark stardescribed by our quark matter EOS model with a gap parameter $\Delta=25$ MeVfrom a fluid compact star if the tidal deformability can be measured to about10% (45%) level. On the other hand, we find that the nuclear matter fluidenvelope of a hybrid star can screen out the effect of the solid coresignificantly so that the resulting I-Love relation for hybrid stars stillagrees with the universal relation for fluid stars to about 1% level.
展开▼
