List questions from weak-derivatives | MathQA

A ball with slit at the radius is not $W^{1,1}$-extension domain

Published on 25 Nov 2022 - 16:01

Chain rule for weak derivatives for composing a Sobolev function with a differentiable function

Published on 27 Nov 2022 - 23:15

Function with weak derivative implies it is continuous.

Published on 28 Nov 2022 - 16:40

If a function $u \in L^p$ in a Lebesgue space has a weak derivative, in what Lebesgue space is the weak derivative?

Published on 03 Dec 2022 - 9:42

Weak derivative of Extension of a function in sobolev space

Published on 20 Dec 2022 - 10:49

The set of $K$ quasiconformal mappings between between the disc fixing the origin is compact

Published on 23 Feb 2026 - 6:38

The converse of Alexandrov theorem: is it true that $f$ is convex iff $f$ is a.e. twice differentiable with positive semidefinite Hessian?

Published on 13 Jan 2023 - 8:24

On the derivative of probability density functions

Published on 15 Jan 2023 - 20:23

Are pointwise solutions also weak?

Published on 27 Mar 2026 - 8:16

Finding weak form of equation with two different functions

Published on 29 Mar 2026 - 10:14