Angular momentum is a key quantity linking the formation of galaxies to the dynamics of the cosmic web. Building on a series of recent observational and theoretical works, this talk will present a picture of how angular momentum is generated, transported and reprocessed across scales—from megaparsec-scale filaments, through galaxy clusters, down to individual galaxies. I will first show how large-scale cosmic filaments can host measurable spin, and how a well-defined characteristic radius provides a robust dynamical boundary for these structures. I will then demonstrate that galaxy clusters act as an intermediate “bridge” in this cosmic dance: using new observational estimators, we can detect statistically significant rotation in clusters and establish systematic alignments between cluster spin, filament axes, and the spins of brightest central galaxies. Finally, I will discuss a two-phase model of galaxy angular momentum evolution, in which galaxies initially acquire spin via laminar accretion perpendicular to filaments and later undergo spin reorientation through mergers and anisotropic inflows along filaments, naturally explaining the observed spin–filament alignment flip with mass and time. Together, these results map out a coherent multi-scale pathway for angular momentum transfer in the Universe, from large-scale structure to the internal dynamics of galaxies.
