Non-radial implosion for compressible Euler and Navier-Stokes in $\mathbb{T}^3$ and $\mathbb{R}^3$
Gonzalo Cao-Labora, Javier Gómez-Serrano, Jia Shi, Gigliola Staffilani
TL;DR
The paper advances the theory of singularity formation in compressible flows by constructing smooth, non-radial imploding solutions to the Euler and Navier–Stokes equations on both $ abla ext{T}^3$ and $ abla ext{R}^3$. It develops a robust linear stability framework around self-similar radial profiles, employing dissipativity, maximality, and a novel angular repulsivity mechanism via vector spherical harmonics to handle non-radial perturbations. The nonlinear analysis combines a truncated linear problem, a high-regularity energy method, and a finite-codimension topological argument to produce finite-time blow-up on a codimension-one manifold of initial data, with well-controlled self-similar profiles $(ar U,ar S)$. This work broadens the scope of imploding singularities beyond radial symmetry and provides a blueprint for extending stability analyses to angular perturbations in fluid PDEs, potentially impacting understanding of wave turbulence and norm inflation phenomena in periodic settings.
Abstract
In this paper we construct smooth, non-radial solutions of the compressible Euler and Navier-Stokes equation that develop an imploding finite time singularity. Our construction is motivated by the works [Merle, Raphaël, Rodnianski, and Szeftel, Ann. of Math., 196(2):567-778, 2022, Ann. of Math., 196(2):779-889, 2022], [Buckmaster, Cao-Labora, and Gómez-Serrano, arXiv:2208.09445, 2022], but is flexible enough to handle both periodic and non-radial initial data.
