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Timeline for Existence of a special function

Current License: CC BY-SA 4.0

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Jul 10, 2020 at 15:38 comment added Bazin Well, near every point of the boundary, you have a local function $\rho$, so that you can cover the boundary by a finite collection of open sets $\{U_k\}_{1\le k\le N}$ to which you add $U_0=\Omega$. Using a partition of unity (see e.g. Section 1.4 in Hörmander's ALPDO I) you can construct a global $\rho$.
Jul 10, 2020 at 1:36 comment added S. Maths @Bazin could you provide a reference to a proof of the existence of such $\rho$? Thanks.
Jun 22, 2020 at 22:44 comment added Bazin Partition of unity.
Jun 22, 2020 at 4:03 comment added LSpice Why can your locally defined function be pieced together to a global function?
Jun 21, 2020 at 21:58 comment added Bazin That removed condition would make the smoothness impossible: the most caricatural case would be the situation where $b$ is reduced to a single point of the boundary.
Jun 21, 2020 at 20:20 comment added MathGeo Thank you. Could you give your opinion about the condition I removed, If we can get something close?
Jun 21, 2020 at 20:18 vote accept MathGeo
Jun 21, 2020 at 19:07 history answered Bazin CC BY-SA 4.0