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Uniqueness of Lipschitz extensions: Minimizing the sup norm of the gradient

✍ Scribed by Robert Jensen


Publisher
Springer
Year
1993
Tongue
English
Weight
1005 KB
Volume
123
Category
Article
ISSN
0003-9527

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✦ Synopsis


In this paper we examine the problem of minimizing the sup norm of the gradient of a function with prescribed boundary values. Geometrically, this can be interpreted as finding a minimal Lipschitz extension. Due to the weak convexity of the functional associated to this problem, solutions are generally nonunique. By adopting G. ARONSSON'S notion of absolutely minimizing we are able to prove uniqueness by characterizing minimizers as the unique solutions of an associated partial differential equation. In fact, we actually prove a weak maximum principle for this partial differential equation, which in some sense is the Euler equation for the minimization problem. This is significantly difficult because the partial differential equation is both fully nonlinear and has very degenerate ellipticity. To overcome this difficulty we use the weak solutions of M. G. CRANDALL and P.-L. LIONS, also known as viscosity solutions, in conjunction with some arguments using integration by parts.


πŸ“œ SIMILAR VOLUMES


On the Lipschitz Regularity of Minimizer
✍ Francesco Siepe πŸ“‚ Article πŸ“… 2001 πŸ› Elsevier Science 🌐 English βš– 181 KB

We prove a Lipschitz regularity result for minimizers of functionals of the calculus of variations of the form f Du x dx, where f is a continuous convex function from n into 0 +∞ , not necessarily depending on the modulus of Du.