Kicking time back in black-hole mergers: Ancestral masses, spins, birth recoils and hierarchical-formation viability of GW190521

Carlos Araújo Álvarez, Henry W. Y. Wong, Anna Liu +1

Pair-instability supernova (PISN) prevents black-hole formation from stellar collapse within the approximate mass range $M\in [65,130]M_{\odot }$. However, such black holes may form h…