Breaking binary formation mechanism degeneracies with gravitational wave clustering

RESUMO

Thanks to the almost 400 gravitational wave events detected, we are currently able to grasp the fundamental features of black hole mass, spin, and distance distributions. However, such a fast increase in the precision of the measurements does not necessarily correspond to a better theoretical understanding of gravitational wave sources, especially in current scenarios where the number of free parameters is significantly larger than the number of inferred properties of the black hole population. In this work, we showcase how the landscape of theoretical models can be chipped away by complementary data-analysis strategies, in particular by studying the statistical properties of gravitational wave anisotropic distribution. Specifically, we show how gravitational wave clustering is sensitive to two unique features of each binary formation mechanism: the time-delay distribution and the properties of the binary hosts. First, we consider a model-agnostic scenario and show the impact that different time-delay distributions have on the gravitational wave bias. Then, we consider a realistic scenario where gravitational wave events are sourced either by isolated binary evolution or dynamical processes in globular clusters, and study how the gravitational wave bias is unique sensitive to the specific properties of the environment. In both scenarios, we show how the cross-correlation between galaxy and gravitational wave catalogs is able to distinguish between models with different time delays or with different binary sub-populations originated in specific formation channels.