Extensions of best approximation and coincidence theorems

Let X be a Hausdorff compact space, E a topological vector space on which E* separates points, F:X→2E an upper semicontinuous multifunction with compact acyclic values, and g:X→E a continuous function such that g(X) is convex and g−1(y) is acyclic for each y∈g(X). Then either (1) there exists an x0∈...

Full description

Saved in:
Bibliographic Details
Main Author: Sehie Park
Format: Article
Language:English
Published: Wiley 1997-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Subjects:
Online Access:http://dx.doi.org/10.1155/S016117129700094X
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832552380710780928
author Sehie Park
author_facet Sehie Park
author_sort Sehie Park
collection DOAJ
description Let X be a Hausdorff compact space, E a topological vector space on which E* separates points, F:X→2E an upper semicontinuous multifunction with compact acyclic values, and g:X→E a continuous function such that g(X) is convex and g−1(y) is acyclic for each y∈g(X). Then either (1) there exists an x0∈X such that gx0∈Fx0 or (2) there exist an (x0,z0) on the graph of F and a continuous seminorm p on E such that 0<p(gx0−z0)≤p(y−z0)         for all         y∈g(X). A generalization of this result and its application to coincidence theorems are obtained. Our aim in this paper is to unify and improve almost fifty known theorems of others.
format Article
id doaj-art-a96145ceb2754663b37ffda17a8cf38f
institution Kabale University
issn 0161-1712
1687-0425
language English
publishDate 1997-01-01
publisher Wiley
record_format Article
series International Journal of Mathematics and Mathematical Sciences
spelling doaj-art-a96145ceb2754663b37ffda17a8cf38f2025-02-03T05:58:48ZengWileyInternational Journal of Mathematics and Mathematical Sciences0161-17121687-04251997-01-0120468969810.1155/S016117129700094XExtensions of best approximation and coincidence theoremsSehie Park0Department of Mathematics, Seoul National University, Seoul 151–742, KoreaLet X be a Hausdorff compact space, E a topological vector space on which E* separates points, F:X→2E an upper semicontinuous multifunction with compact acyclic values, and g:X→E a continuous function such that g(X) is convex and g−1(y) is acyclic for each y∈g(X). Then either (1) there exists an x0∈X such that gx0∈Fx0 or (2) there exist an (x0,z0) on the graph of F and a continuous seminorm p on E such that 0<p(gx0−z0)≤p(y−z0)         for all         y∈g(X). A generalization of this result and its application to coincidence theorems are obtained. Our aim in this paper is to unify and improve almost fifty known theorems of others.http://dx.doi.org/10.1155/S016117129700094Xmultifunctionupper semicontinuous (u.s.c.)acyclicconvex spaceadmissible classbest approximationmetric projectioninward [outward] set.
spellingShingle Sehie Park
Extensions of best approximation and coincidence theorems
International Journal of Mathematics and Mathematical Sciences
multifunction
upper semicontinuous (u.s.c.)
acyclic
convex space
admissible class
best approximation
metric projection
inward [outward] set.
title Extensions of best approximation and coincidence theorems
title_full Extensions of best approximation and coincidence theorems
title_fullStr Extensions of best approximation and coincidence theorems
title_full_unstemmed Extensions of best approximation and coincidence theorems
title_short Extensions of best approximation and coincidence theorems
title_sort extensions of best approximation and coincidence theorems
topic multifunction
upper semicontinuous (u.s.c.)
acyclic
convex space
admissible class
best approximation
metric projection
inward [outward] set.
url http://dx.doi.org/10.1155/S016117129700094X
work_keys_str_mv AT sehiepark extensionsofbestapproximationandcoincidencetheorems