| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4660470 | Topology and its Applications | 2007 | 14 Pages |
Abstract
Some ways to obtain upper and lower bounds for measures of noncompactness of retractions onto spheres in infinite-dimensional normed spaces are discussed. Moreover, relations with 0-epi maps are revealed and the extension of condensing maps on spheres is discussed. As an application, some results of Birkhoff–Kellog type and Nussbaum's fixed point theorem on spheres are obtained.
Related Topics
Physical Sciences and Engineering
Mathematics
Geometry and Topology
