Surveys in Mathematics and its Applications

ISSN 1842-6298 (electronic), 1843-7265 (print)
Volume 21 (2026), 219 -- 232
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This work is licensed under a Creative Commons Attribution 4.0 International License.

KKM MAPS AND LERAY--SCHAUDER TYPE FIXED POINT THEORY

Donal O'Regan

Abstract. In this paper we establish new fixed point theory and Leray-Schauder type alternatives for KKM type maps. The arguments are based on new composition and product properties for KKM type maps and an Urysohn type lemma in completely regular spaces.

2020 Mathematics Subject Classification: 47H10; 54H25.
Keywords: Fixed points; KKM maps; Leray--Schauder alternatives

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References

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Donal O'Regan, ORCID: https://orcid.org/0000-0002-4096-1469
School of Mathematical and Statistical Sciences,
University of Galway,
Galway, Ireland.
e-mail: donal.oregan@nuigalway.ie



Received: July 08, 2026; Accepted: September 21, 2026
Published electronically: September 24, 2026