Extremal points of a functional on the set of convex functions
We investigate the extremal points of a functional \int f(\nabla u), for a convex or concave function f. The admissible functions u:\Omega\subset\RN\to\bR are convex themselves and satisfy a condition u_2\leq u \leq u_1. We show that the extremal points are exactly u_1 and u_2 if these functions are...
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Published in: | Proceedings of the American Mathematical Society Vol. 127; no. 6; pp. 1723 - 1727 |
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Main Authors: | , |
Format: | Journal Article |
Language: | English |
Published: |
American Mathematical Society
01-06-1999
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Subjects: | |
Online Access: | Get full text |
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Summary: | We investigate the extremal points of a functional \int f(\nabla u), for a convex or concave function f. The admissible functions u:\Omega\subset\RN\to\bR are convex themselves and satisfy a condition u_2\leq u \leq u_1. We show that the extremal points are exactly u_1 and u_2 if these functions are convex and coincide on the boundary \partial\Omega. No explicit regularity condition is imposed on f, u_1, or u_2. Subsequently we discuss a number of extensions, such as the case when u_1 or u_2 are non-convex or do not coincide on the boundary, when the function f also depends on u, etc. |
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ISSN: | 0002-9939 1088-6826 |
DOI: | 10.1090/S0002-9939-99-05209-0 |