ArticleOriginal scientific text

Title

Borel partitions of unity and lower Carathéodory multifunctions

Authors 1

Affiliations

  1. Stat-Math Unit, Indian Statistical Institute 203 B.T. Road Calcutta 700 035, India

Abstract

We prove the existence of Carathéodory selections and representations of a closed convex valued, lower Carathéodory multifunction from a set A in A((X)) into a separable Banach space Y, where ℰ is a sub-σ-field of the Borel σ-field ℬ(E) of a Polish space E, X is a Polish space and A is the Suslin operation. As applications we obtain random versions of results on extensions of continuous functions and fixed points of multifunctions. Such results are useful in the study of random differential equations and inclusions and in mathematical economics.   As a key tool we prove that if A is an analytic subset of E × X and if {Un:nw} is a sequence of Borel sets in A such that A=nUn and the section Un(e) is open in A(e), e ∈ E, n ∈ w, then there exist Borel functions pn:A[0,1], n ∈ w, such that for every e ∈ E, {pn(e,·):nw} is a locally Lipschitz partition of unity subordinate to {Un(e):nw}.

Keywords

Carathéodory functions and multifunctions, Carathéodory selections, fixed points

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Additional information

http://matwbn.icm.edu.pl/ksiazki/fm/fm146/fm14633.pdf

Pages:
239-249
Main language of publication
English
Received
1993-08-24
Accepted
1994-07-27
Published
1995
Exact and natural sciences