Structure of the crease and singular boundary for the 3D relativistic Euler equations

Under the assumptions of the time-of-first-blowup conjecture, let the perturbed solution be the development of smooth initial data close to a simple isentropic plane-symmetric background solution. Let the background solution have a crease and singular boundary, and let the corresponding perturbed objects be defined in the perturbed maximal globally hyperbolic development.

Crease-and-singular-boundary conjecture. The perturbed solution has a crease and singular boundary that are perturbations of the crease and singular boundary of the background solution.

The conjecture predicts stability of the geometric structure accompanying shock formation under general perturbations with vorticity and entropy. The background and conjectured perturbed structures are illustrated in the figures cited by the source, while the assertion itself remains open.