Miller Andrew L, Aggarwal Nancy, Clesse Sébastien, De Lillo Federico, Sachdev Surabhi, Astone Pia, Palomba Cristiano, Piccinni Ornella J, Pierini Lorenzo
<a href="https://ror.org/00f9tz983">Nikhef-National Institute for Subatomic Physics</a>, Science Park 105, 1098 XG Amsterdam, The Netherlands.
Institute for Gravitational and Subatomic Physics (GRASP), <a href="https://ror.org/04pp8hn57">Utrecht University</a>, Princetonplein 1, 3584 CC Utrecht, The Netherlands.
Phys Rev Lett. 2024 Sep 13;133(11):111401. doi: 10.1103/PhysRevLett.133.111401.
Gravitational waves from subsolar mass inspiraling compact objects would provide almost smoking-gun evidence for primordial black holes (PBHs). We perform the first search for inspiraling planetary-mass compact objects in equal-mass and highly asymmetric mass-ratio binaries using data from the first half of the LIGO-Virgo-KAGRA third observing run. Though we do not find any significant candidates, we determine the maximum luminosity distance reachable with our search to be of O(0.1-100) kpc, and corresponding model-independent upper limits on the merger rate densities to be O(10^{3}-10^{-7}) kpc^{-3} yr^{-1} for systems with chirp masses of O(10^{-4}-10^{-2})M_{⊙}, respectively. Furthermore, we interpret these rate densities as arising from PBH binaries and constrain the fraction of dark matter that such objects could comprise. For equal-mass PBH binaries, we find that these objects would compose less than 4%-100% of DM for PBH masses of 10^{-2}M_{⊙} to 2×10^{-3}M_{⊙}, respectively. For asymmetric binaries, assuming one black hole mass corresponds to a peak in the mass function at 2.5M_{⊙}, a PBH dark-matter fraction of 10% and a second, much lighter PBH, we constrain the mass function of the second PBH to be less than 1 for masses between 1.5×10^{-5}M_{⊙} and 2×10^{-4}M_{⊙}. Our constraints, recently released, are robust enough to be applied to any PBH or exotic compact object binary formation models, and complement existence microlensing results.
来自低于太阳质量的致密天体相互环绕产生的引力波，几乎能为原初黑洞（PBH）提供确凿证据。我们利用激光干涉引力波天文台（LIGO）-处女座（Virgo）-神乐（KAGRA）第三次观测运行前半期的数据，首次对质量相等和质量比高度不对称的双星系统中相互环绕的行星质量致密天体进行了搜索。尽管我们未发现任何显著候选天体，但确定了此次搜索可达到的最大光度距离为O(0.1 - 100) 千秒差距，对于啁啾质量为O(10⁻⁴ - 10⁻²)M⊙的系统，相应的与模型无关的合并率密度上限分别为O(10³ - 10⁻⁷) 千秒差距⁻³ 年⁻¹。此外，我们将这些率密度解释为由PBH双星产生，并限制了此类天体可能构成的暗物质比例。对于质量相等的PBH双星，我们发现对于质量在10⁻²M⊙到2×10⁻³M⊙之间的PBH，这些天体分别占暗物质的比例小于4% - 100%。对于不对称双星，假设一个黑洞质量对应于质量函数在2.5M⊙处的峰值、PBH暗物质比例为10%以及另一个质量轻得多的PBH，我们将第二个PBH的质量函数限制为在1.5×10⁻⁵M⊙和2×10⁻⁴M⊙之间的质量小于1。我们最近发布的这些限制足够稳健，可应用于任何PBH或奇异致密天体双星形成模型，并补充了现有微引力透镜结果。
