Constraints on interquark interaction parameters with GW170817 in a binary strange star scenario

Abstract

The LIGO/VIRGO detection of the gravitational waves from a binary merger system, GW170817, has put a clean and strong constraint on the tidal deformability of the merging objects. From this constraint, deep insights can be obtained in compact star equation of states, which has been one of the most puzzling problems for nuclear physicists and astrophysicists. Employing one of the most widely-used quark star EOS model, we characterize the star properties by the strange quark mass (ms), an effective bag constant (B eff ), the perturbative QCD correction (a4), as well as the gap parameter (∆) when considering quark pairing, and investigate the dependences of the tidal deformablity on them. We find that the tidal deformability is dominated by B eff , and insensitive to ms, a4. We discuss the correlation between the tidal deformability and the maximum mass (MTOV) of a static quark star, which allows the model possibility to rule out the existence of quark stars with future gravitational wave observations and mass measurements. The current tidal deformability measurement implies MTOV ≤ 2.18 M (2.32 M when pairing is considered) for quark stars. Combining with two-solarmass pulsar observations, we also make constraints on the poorly known gap parameter ∆ for color-flavorlocked quark matter.

Observing the post-merger signal of GW170817-like events with improved gravitational-wave detectors

“…Indeed, premerger data from GW170817 have been used to measure the tidal parameters and radii of the coalescing NSs [5,[51][52][53][54][55][56][57][58][59][60][61][62][63][64], and to place constraints on their EoS, yielding results in agreement with terrestrial experiments [65]. However, the post-merger emission of GW170817 remained undetected [5,63,66].…”

Probing up-down quark matter via gravitational waves

“…Note that some SQS studies [21,32,46] exploited similar small B eff to have maximum masses above 2 M , but the smallness is not natural considering the appearance of strangeness, and a large perturbative QCD (pQCD) effect or a color-superconducting phase has to be included to guarantee the stability. Another difference is the large strange quark mass that affects their results but does not enter our study of udQS study here.…”

Holographic compact stars meet gravitational wave constraints

“…It has been suggested long ago that in a coalescing binary system of two NSs, or a black hole and a NS, the tidal forces between the two objects affect the gravitational wave signal in a way that can be measured using Earth-based gravitational wave detectors [73][74][75][76][77][78][79][80][81]. In the fall of 2017, LIGO and Virgo were indeed able to place a quantitative limit on these effects in their analysis of gravitational wave data that very likely had their origins in the merger of two NSs [46] (see also the analyses of [82][83][84][85][86][87][88][89][90][91][92][93]). The limit was provided for the tidal deformabilities of the two stars involved in the merger -a quantity related to the Love numbers of the stars that measures their susceptibility to the tidal forces that deform their shape.…”