Filament Vorticity Hints

Recent surveys have detected hints of coherent vorticity — rotational motion transverse to the spine — in cosmic filaments. Within ΛCDM, vorticity cannot be generated by linear perturbation theory from Gaussian initial conditions, and any large-scale vorticity must arise from nonlinear mode coupling during structure formation, which produces only small, incoherent vortical flows at late times. Coherent filament vorticity on scales of tens of megaparsecs therefore poses a significant challenge for ΛCDM, requiring either unusual initial conditions or unidentified driving mechanisms. SCT predicts exactly this coherent vorticity through angular momentum inheritance. The collision impact parameter deposits a net angular momentum vector into the thermalized debris, and this angular momentum cascades from the large-scale collision geometry down through the filament network via the hierarchical structure formation process.

Each filament that forms along the primary collision axis inherits a component of the original angular momentum proportional to its mass and its alignment with the collision geometry. This inherited angular momentum manifests as coherent vortical flows around filament spines — material spiraling around the spine axis as it accretes, rather than purely radially infalling. The vorticity direction is correlated across multiple filaments because they all inherited from the same collision angular momentum vector, explaining why the hints of vorticity appear to have coherent orientation across large regions of the cosmic web. ΛCDM has no mechanism for this coherence: its tidal torquing generates vorticity with random orientations in different filaments. The coherent, axis-correlated vorticity seen in observations is a natural prediction of SCT and a potential probe of the original collision angular momentum vector.