|
This article is cited in 7 scientific papers (total in 7 papers)
Convexity of Chebyshev Sets Contained in a Subspace
A. R. Alimov M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics
Abstract:
Convex Chebyshev sets $M$ in a linear space $X$ with norm or nonsymmetric norm $(X,\|\cdot\|)$ which are contained in a subspace $H$ of $X$ are considered. It is proved that if $|\cdot|_{H,\theta}$ is the nonsymmetric norm on $H$ determined by the Minkowski functional of $(B-\theta)\cap H$, where $B$ is the unit ball of $X$ and $\|\theta\|<1$, with respect to 0, then $M$ is a Chebyshev set in $(H,|\cdot|_{H,\theta})$ for any $\theta$. From this result sufficient and necessary conditions for the convexity of Chebyshev sets and bounded Chebyshev sets contained in a subspace $H$ of $X$ are derived.
Received: 03.02.2004 Revised: 22.11.2004
Citation:
A. R. Alimov, “Convexity of Chebyshev Sets Contained in a Subspace”, Mat. Zametki, 78:1 (2005), 3–15; Math. Notes, 78:1 (2005), 3–13
Linking options:
https://www.mathnet.ru/eng/mzm2555https://doi.org/10.4213/mzm2555 https://www.mathnet.ru/eng/mzm/v78/i1/p3
|
Statistics & downloads: |
Abstract page: | 425 | Full-text PDF : | 227 | References: | 51 | First page: | 1 |
|