Two-part proof claims global smoothness for 3D Navier–Stokes by reducing the full problem to an axisymmetric case
This paper presents a long, technical argument that aims to prove global smooth continuation for all smooth, finite-energy solutions of the three‑dimensional incompressible Navier–Stokes equations. The author divides the work into two parts. Part I treats flows that are axisymmetric with swirl (that is, symmetric around an axis but allowed to rotate about that axis). Part II argues that any hypothetical singularity in the full three‑dimensional flow must reduce to one of the cases handled by Part I or to a classical two‑dimensional case, both of which the paper claims are nonsingular. Together the two parts are offered as a proof that smooth solutions never blow up in finite time for the 3D Navier–Stokes system described in the paper.
In Part I the argument is carried out in a mathematical rewriting called a five‑dimensional lift. This is not a new physical space but an exact way to represent axisymmetric scalars as radial functions in R4 plus the axial direction. The central unknowns in that formulation are G = ω_θ/r (a vorticity ratio), F = u^θ/r (a regularized measure of swirl), and H = F^2 (a squared source density). The key observation is that a derivative source term and a compressive feedback term act together as a single “pair‑transfer” mechanism between G and H. The proof combines many classical analytic tools — localized energy identities, the Hardy–Littlewood–Sobolev (HLS) inequality, Sobolev interpolation, compactness arguments, and a Pohozaev–Morawetz identity — to show that this pair cannot sustain a terminal singular packet in the axisymmetric class.
Part II is a front‑end reduction that begins by assuming a hypothetical terminal singular packet in the full three‑dimensional flow. The paper decomposes every possible obstruction into named channels (for example: leakage, shell, pressure, tail, fragmentation, passive‑strain, angular phase‑lock, and transfer‑active temporal channels). Each channel is analyzed and either shown to produce a finite‑overlap descendant (a kind of dispersal that prevents concentration) or to incur a strict terminal loss. If no final defect remains, the active part of the flow must fall into one of two rigid classes: a locally two‑dimensional flow or an axisymmetric‑with‑swirl flow around a fixed axis. The two‑dimensional alternative is excluded by classical 2D theory, and the axisymmetric alternative is handled by Part I, so the reduction is intended to rule out any genuine 3D singularity.