Let C be a closed bounded convex subset of a Banach space E which has the origin of E as an interior point and let p C denote the Minkowski functional with respect to C. Given a closed set X/E and a point u # E we consider a minimization problem min C (u, X ) which consists in proving the existence
On Well Posed Generalized Best Approximation Problems
โ Scribed by Chong Li
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 143 KB
- Volume
- 107
- Category
- Article
- ISSN
- 0021-9045
No coin nor oath required. For personal study only.
โฆ Synopsis
Let C be a closed bounded convex subset of X with 0 being an interior point of C and p C be the Minkowski functional with respect to C. Let G be a nonempty closed, boundedly relatively weakly compact subset of a Banach space X. For a point x # X, we say the minimization problem min C (x, G) is well posed if there exists a unique point zร such that p C (zร &x)=* C (x, G) and every sequence [z n ]/G satisfying lim n ร p C (z n &x)=* C (x, G) converges strongly to the point zร , where * C (x, G)=inf z # G p C (z&x). Under the assumption that C is both strictly convex and Kadec, we prove that the set X o (G) of all x # X such that the problem min C (x, G) is well posed is a residual subset of X extending the results in the case that the modulus of convexity of C is strictly positive due to Blasi and Myjak. In addition, we also prove these conditions are necessary.
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