×

On Krasnoselskii’s cone fixed point theorem. (English) Zbl 1203.47029

Summary: In recent years, the Krasnoselskii fixed point theorem for cone maps and its many generalizations have been successfully applied to establish the existence of multiple solutions in the study of boundary value problems of various types. In the first part of this paper, we revisit the Krasnoselskii theorem, in a more topological perspective, and show that it can be deduced in an elementary way from the classical Brouwer-Schauder theorem. This viewpoint also leads to a topology-theoretic generalization of the theorem. In the second part of the paper, we extend the cone theorem in a different direction using the notion of retraction and show that a stronger form of the often cited Leggett-Williams theorem is a special case of this extension.

MSC:

47H10 Fixed-point theorems
47H07 Monotone and positive operators on ordered Banach spaces or other ordered topological vector spaces

References:

[6] doi:10.1016/0022-0396(88)90081-2 · Zbl 0671.35024 · doi:10.1016/0022-0396(88)90081-2
[8] doi:10.1137/1018114 · Zbl 0345.47044 · doi:10.1137/1018114
[10] doi:10.1098/rsta.1971.0053 · Zbl 0226.76037 · doi:10.1098/rsta.1971.0053
[11] doi:10.1016/0022-0396(73)90053-3 · Zbl 0311.34087 · doi:10.1016/0022-0396(73)90053-3
[12] doi:10.1007/BF01362380 · Zbl 0064.35703 · doi:10.1007/BF01362380
[16] doi:10.1007/s11784-007-0027-4 · Zbl 1134.47041 · doi:10.1007/s11784-007-0027-4
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.