On Asymptotic Centers and Fixed Points of Nonexpansive Mappings
- 1 February 1980
- journal article
- Published by Canadian Mathematical Society in Canadian Journal of Mathematics
- Vol. 32 (2) , 421-430
- https://doi.org/10.4153/cjm-1980-033-5
Abstract
Let X be a Banach space and B a bounded subset of X. For each x ∈ X, define R(x) = sup{‖x – y‖ : y ∈ B}. If C is a nonempty subset of X, we call the number R = inƒ{R(x) : x ∈ C} the Chebyshev radius of B in C and the set the Chebyshev center of B in C. It is well known that if C is weakly compact and convex, then and if, in addition, X is uniformly convex, then the Chebyshev center is unique; see e.g., [9].Let {Bα : α ∈ ∧} be a decreasing net of bounded subsets of X. For each x ∈ X and each α ∈ ∧, defineKeywords
This publication has 0 references indexed in Scilit: