Astrophysical Implications of Eccentric Black Hole Mergers

Eccentricity in binary black hole mergers is a clear sign that some kind of dynamical processes were responsible for the coalescence of the binary. In this talk, I will overview eccentricity predictions from various dynamical formation channels, and what an eccentric gravitational-wave detection would imply for binary black hole formation channels. Given the robust predictions for the eccentricity distribution in dense star clusters, I will show how a single confident eccentric detection (or lack thereof) in the upcoming observing run of the LIGO—Virgo—KAGRA network will allow for stringent constraints on the fraction of merging systems that have a dynamical origin. I will also discuss the redshift evolution of the eccentricity distribution, which will be apparent with next-generation gravitational-wave detectors, and the astrophysical quandaries the quantification of this effect will answer.