On the Structure of the Complements of Chebyshev Sets
Funkcionalʹnyj analiz i ego priloženiâ, Tome 35 (2001) no. 3, pp. 19-27
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A set is called a Chebyshev set if it contains a unique best approximation element. We study the structure of the
complements of Chebyshev sets, in particular considering the following question: How many connected components can the complement of a Chebyshev set in a finite-dimensional normed or nonsymmetrically normed linear space have? We extend some results from [A. R. Alimov, East J. Approx, 2, No. 2, 215–232 (1996)]. A. L. Brown's characterization of four-dimensional normed linear spaces in which every Chebyshev set is convex is extended to the nonsymmetric setting. A characterization of finite-dimensional spaces that contain a strict sun whose complement has a given number of connected components is established.
@article{FAA_2001_35_3_a1,
author = {A. R. Alimov},
title = {On the {Structure} of the {Complements} of {Chebyshev} {Sets}},
journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
pages = {19--27},
publisher = {mathdoc},
volume = {35},
number = {3},
year = {2001},
language = {ru},
url = {http://geodesic.mathdoc.fr/item/FAA_2001_35_3_a1/}
}
A. R. Alimov. On the Structure of the Complements of Chebyshev Sets. Funkcionalʹnyj analiz i ego priloženiâ, Tome 35 (2001) no. 3, pp. 19-27. http://geodesic.mathdoc.fr/item/FAA_2001_35_3_a1/