Self-similar singularity profiles for two-dimensional Boussinesq

Which self-similar profiles can describe blow-up in the two-dimensional Boussinesq equations, and what are their linearized unstable modes? Stable and unstable profiles are separate targets; numerically small residuals provide candidates rather than a rigorous existence theorem.

Why it matters and what counts as progress

Why it matters: Unstable self-similar profiles reveal additional candidate blow-up branches not covered by proofs for related stable profiles.

What counts as progress: Find additional profiles with controlled residuals and stability calculations, or prove that a numerical candidate corresponds to an exact solution.

How the problem developed

  1. 17 Sept 2025 · Numerical discovery [1]

    Yongji Wang and coauthors Reported one stable and three unstable self-similar Boussinesq profiles, with residuals of orders 10⁻⁸ to 10⁻⁷; a fourth unstable profile remained an unvalidated candidate.

AI contribution

Discovery of Unstable Singularities

Yongji Wang, Mehdi Bennani, James Martens, Sébastien Racanière, Sam Blackwell, Alex Matthews, Stanislav Nikolov, Gonzalo Cao-Labora, Daniel S. Park, Martin Arjovsky, Daniel Worrall, Chongli Qin, Ferran Alet, Borislav Kozlovskii, Nenad Tomašev, Alex Davies, Pushmeet Kohli, Tristan Buckmaster, Bogdan Georgiev, Javier Gómez-Serrano, Ray Jiang, Ching-Yao Lai

Wang and collaborators report a second unstable self-similar Córdoba–Córdoba–Fontelos (CCF) profile, stable and three unstable incompressible porous media (IPM) profiles, and stable and three unstable 2D Boussinesq profiles. They test residuals and linearized modes on dense grids. A fourth Boussinesq profile remains an unvalidated candidate.

AI involvementAI-centered
ImportanceNotable
Technical verificationPartial
Human understandingFull
Paper date:

Sources

  1. Yongji Wang et al., Discovery of Unstable Singularities
  2. Wang and collaborators’ unstable-singularity study
  3. Follow-up numerical refinements
Website timeline

Publication dates and editorial changes.