Speaker
Description
Gravitational waves from sub-solar 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 $\mathcal{O}(0.1-100)$ kpc, and corresponding model-independent upper limits on the merger rate densities to be $\mathcal{O}(10^{3}-10^{-7})$ kpc$^{-3}$yr$^{-1}$ for systems with chirp masses of $\mathcal{O}(10^{-4}-10^{-2})M_\odot$, 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 $10^{-2}M_\odot$ to $2\times 10^{-3}M_\odot$, respectively. For asymmetric binaries, assuming one black hole mass corresponds to a peak in the mass function at 2.5$M_\odot$, 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 $1.5\times 10^{-5}M_\odot$ and $2\times 10^{-4}M_\odot$. Our constraints, released on Zenodo, are robust enough to be applied to any PBH or exotic compact object binary formation models, and complement existing microlensing results.
