Establish the mechanisms that harden massive multiple-star systems to tight separations

Establish the dynamical processes that harden massive multiple-star systems to tight separations, quantifying the roles and relative importance of disc-driven torques, turbulent gas dynamics, and few-body interactions during the embedded formation phase.

Background

The authors discuss observational and theoretical indications that massive binaries can undergo significant hardening shortly after formation, but emphasize that the specific processes responsible for this evolution are not firmly identified. They highlight disc interactions, turbulence, and multi-body dynamics as possible contributors.

Their simulation aims to capture early hardening due to gas dynamics and stellar interactions, yet the introduction explicitly flags the overall dynamical evolution and hardening pathways as unclear, reflecting a field-level uncertainty.