Fixed point theorems for multifunctions in topological vector spaces (Q1340523)

The authors prove two fixed point theorems for multifunctions with closed convex values and (weakly) closed graphs in topological vector spaces. This extends previous work by \textit{O. Hadzić} [Nonlin. Anal. Theory Methods Appl. 5, 1009-1019 (1981; Zbl 0473.47046)], \textit{A. Idzik} [Proc. Am. Math. Soc. 104, No. 3, 779-784 (1988; Zbl 0691.47046)], \textit{G. Tian} [J. Math. Anal. Appl. 158, No. 1, 161-167 (1991; Zbl 0735.47037)] and their own [Riv. Mat. Univ. Parma, IV. Ser. 17, 59-67 (1991; Zbl 0810.47050)].