Dr. Sreejith Nair

This paper investigates a proposed formation channel for subsolar-mass compact-object mergers arising from fragmentation inside collapsar accretion disks. Using numerical-relativity simulations of hierarchical subsolar-mass mergers in a disk-like environment, the authors show that repeated mergers and recoil kicks can generate significant orbital eccentricity. They further demonstrate that, because the system has a short lifetime, a non-negligible eccentricity may survive until the final merger. The work suggests that eccentricity in future subsolar-mass gravitational-wave candidates could provide an important signature of hierarchical formation in collapsar disks.