DOI: 10.68381/jca21062 ISSN: 0944-6532

Gelfand Integral of Multifunctions

Kazimierz Musiał

It has been proven by Cascales, Kadets and Rodriguez [J. Convex Anal. 18 (2011), 873-895] that each weak

^* ∗
scalarly integrable multifunction (with respect to a probability measure μ, whose values are compact convex subsets of a conjugate Banach space
X^* X ∗
and the family of support functions determined by X is order bounded in
L_1(\mu) L 1 ( μ )
, is Gelfand integrable in the family of weakly compact convex subsets of
X^* X ∗
. A question has been posed whether a similar result holds true for multifunctions with weakly compact convex values. We prove that the answer is affirmative if X does not contain any isomorphic copy of
l_1 l 1
. If moreover the multifunction is compact valued, then it is Gelfand integrable in the family of compact convex subsets of
X^* X ∗
.