Stable Singularity of the Euler Equations on $\mathbb{R}^3$

Abstract: We provide evidence of a stable finite-time singularity in the 3D Euler equations on the unbounded domain. Using a physics-informed neural network (PINN) with a self-similar ansatz, we find an approximate singular profile for the Euler system at the critical blowup rate of $0.5$ and certify it using a spline representation. The transport field associated with the obtained profile suggests that linear damping can be established throughout the domain, providing strong evidence for the overall stability of the candidate profile. We also establish a complete framework for proving nonlinear stability of the approximate self-similar profile, reducing the analysis to a large but finite collection of explicit estimates and computable constants.