Special Year 2021-22: h-Principle and Flexibility in Geometry and PDEs

An immersion from a smooth n-dimensional manifold $M$ into $R^q$ is called totally nonparallel if, for every pair of distinct points $x$ and $y$ in $M$, the tangent spaces at $f(x)$ and $f(y)$ contain no parallel lines. The simplest example is the...

The incompressible 3D Euler equations have total kinetic energy conservation for smooth (spatially periodic) solutions. In the recent resolution of the Onsager conjecture by Isett, on the other hand, below certain threshold Hölder regularity, Euler...