The landscape of intermediate-mass black-hole binaries with next-generation ground-based detectors*

Intermediate-mass black holes (IMBHs) with masses between 100 and 10000 solar masses remain elusive despite decades of observational searches. Their existence and properties hold crucial implications for our understanding of galaxy formation and evolution, as well as for the growth of supermassive black holes. Next-generation ground-based gravitational-wave observatories, such as the Einstein Telescope and Cosmic Explorer, will be sensitive to lower frequencies than currently accessible, allowing to probe the low end of the IMBH mass range. In this work, we assess the prospects for detection and characterization of IMBH binaries with next-generation detectors. We compare different choices of detector networks and low-frequency sensitivity limits. We use an information-matrix formalism to provide estimates of the errors on IMBH parameters over a large region of the parameter space. Our results are agnostic to IMBH formation channels and can be used in conjunction with population synthesis codes.