We present the first search for gravitational waves from the coalescence of stellar mass and subsolar mass black holes with masses between $20–100M_{\odot }$ and $0.01–1M_{\odot }(10–{10}^3{M}_J)$, respectively. The observation of a single subsolar mass black hole would establish the existence of primordial black holes and a possible component of dark matter. We search the $\sim 164$ day of public LIGO data from 2015–2017 when LIGO-Hanford and LIGO-Livingston were simultaneously observing. We find no significant candidate gravitational-wave signals. Using this nondetection, we place a 90% upper limit on the rate of $30–0.01M_{\odot }$ and $30–0.1M_{\odot }$ mergers at $<1.2\times {10}^6$ and $<1.6\times {10}^4{\mathrm{Gpc}}^{-3}{\mathrm{yr}}^{-1}$, respectively. If we consider binary formation through direct gravitational-wave braking, this kind of merger would be exceedingly rare if only the lighter black hole were primordial in origin ($<{10}^{-4}{\mathrm{Gpc}}^{-3}{\mathrm{yr}}^{-1}$). If both black holes are primordial in origin, we constrain the contribution of $1(0.1)M_{\odot }$ black holes to dark matter to $<0.3(3)\%$.

• Received 8 July 2020
• Accepted 11 December 2020

DOI:https://doi.org/10.1103/PhysRevLett.126.021103

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by the Max Planck Society.

Published by the American Physical Society