Previous |  Up |  Next

Article

Keywords:
pseudo-contractive mappings
Summary:
Let $X$ be a real Banach space. A multivalued operator $T$ from $K$ into $2^X$ is said to be pseudo-contractive if for every $x,y$ in $K$, $u\in T(x)$, $v\in T(y)$ and all $r>0$, $\|x-y\|\leq \|(1+r)(x-y)-r(u-v)\|$. Denote by $G(z,w)$ the set $\{u\in K :\|u-w\|\leq \|u-z\|\}$. Suppose every bounded closed and convex subset of $X$ has the fixed point property with respect to nonexpansive selfmappings. Now if $T$ is a Lipschitzian and pseudo-contractive mapping from $K$ into the family of closed and bounded subsets of $K$ so that the set $G(z,w)$ is bounded for some $z\in K$ and some $w\in T(z)$, then $T$ has a fixed point in $K$.
References:
[1] Browder F.E.: Nonlinear mappings of nonexpansive and accretive type in Banach spaces. Bull. Amer. Math. Soc. 73 (1967), 875-882. MR 0232255 | Zbl 0176.45302
[2] Canetti A., Marino G., Pietramala P.: Fixed point theorems for multivalued mappings in Banach spaces. Nonlinear Analysis, T.M.A. 17 (199011-20). MR 1113446 | Zbl 0765.47016
[3] Downing D., Kirk W.A.: Fixed point theorems for set-valued mappings in metric and Banach spaces. Math. Japonica 22 (1977), 99-112. MR 0473934 | Zbl 0372.47030
[4] Goebel K., Kuczumow T.: A contribution to the theory of nonexpansive mappings. preprint. MR 0584472 | Zbl 0437.47040
[5] Kato T.: Nonlinear semigroups and evolution equations. J. Math. Soc. Japan 19 (1967), 508-520. MR 0226230 | Zbl 0163.38303
[6] Kirk W.A., Ray W.O.: Fixed point theorems for mappings defined on unbounded sets in Banach spaces. Studia Math 64 (1979), 127-138. MR 0537116 | Zbl 0412.47033
[7] Morales C.H.: Pseudo-contractive mappings and the Leray-Schauder boundary condition. Comment. Math. Univ. Carolinae 20 (1979), 745-756. MR 0555187 | Zbl 0429.47021
[8] Morales C.H.: Remarks on pseudo-contractive mappings. J. Math. Anal. Appl. 87 (1982), 158-164. Zbl 0486.47030
[9] Morales C.H.: Set-valued mappings in Banach spaces. Houston J. Math. 9 (1983), 245-253. MR 0703273 | Zbl 0523.47038
[10] Nadler S.B., Jr.: Multi-valued contraction mappings. Pacific J. Math. 30 (1969), 475-488. MR 0254828 | Zbl 0187.45002
[11] Ray W.O.: The fixed point property and unbounded sets in Hilbert space. Trans. Amer. Math. Soc. 258 (1980), 531-537. MR 0558189 | Zbl 0433.47026
[12] Ray W.O.: Zeros of accretive operators defined on unbounded sets. Houston J. Math. 5 (1979), 133-139. MR 0533647 | Zbl 0412.47032
Partner of
EuDML logo