Channelled versus Isotropic Accretion of Galaxy Groups onto Clusters: Kinematics, Spin Alignment, and Assembly Bias

Galaxy clusters grow by accreting groups from the cosmic web, but whether the route of infall (along a cluster-connected filament or from the open field) imprints a group's kinematics, spin, and orbit remains unmeasured at scale. We classify $212{,}704$ group-cluster infall pairs across $27{,}029$ c