Standard cosmological structure formation attributes the peculiar veloc-ity of the Local Group primarily to the gravitational potential of large-scaleoverdensities, most notably the Great Attractor (GA) region. In linear per-turbation theory, this large-scale flow is strictly irrotational 5, 1. This paperintroduces an exploratory, phenomenological numerical framework that ex-tends the standard gravity-only infall model by incorporating a continuous-medium vortex-coupling term, mathematically analogous to a macroscopic Magnus or Coriolis force, modeled as avortex = κ(ωbg ×v). Integrating thiscoupled system over an idealized 18 Gyr timeline using a Navarro-Frenk-White (NFW) gravitational profile 4 anchored to a 600 km/s local infallcalibration 2, we identify a distinct kinematic fingerprint: a cumulative,non-decaying velocity-direction rotation of 21.4◦, even as the spatial trajec-tory remains highly linear due to Hubble-drag suppression. Furthermore,a non-physical high-gravity stress test demonstrates the topological capac-ity of this coupling to induce a 132◦ orbital wrap, strictly avoiding radial singularities. We propose that if the intergalactic medium exhibits effective macroscopic shear, its signature will not manifest as gross orbital deviations,but as coherent transverse velocity residuals (∆v⊥) within modern bulk-flow catalogs 7, 8
Hung Hsiang Chien (Thu,) studied this question.