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Title: Inferring the Intermediate-mass Black Hole Number Density from Gravitational-wave Lensing Statistics
Abstract The population properties of intermediate-mass black holes remain largely unknown, and understanding their distribution could provide a missing link in the formation of supermassive black holes and galaxies. Gravitational-wave observations can help fill in the gap from stellar mass black holes to supermassive black holes with masses between ∼100–10 4 M ⊙ . In our work, we propose a new method for examining lens populations through lensing statistics of gravitational waves, here focusing on inferring the number density of intermediate-mass black holes through hierarchical Bayesian inference. Simulating ∼200 lensed gravitational-wave signals, we find that existing gravitational-wave observatories at their design sensitivity could either constrain the number density of 10 6 Mpc −3 within a factor of 10, or place an upper bound of ≲10 4 Mpc −3 if the true number density is 10 3 Mpc −3 . More broadly, our method leaves room for incorporation of additional lens populations, providing a general framework for probing the population properties of lenses in the universe.
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The Astrophysical Journal Letters
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National Science Foundation
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