A fixed point theorem

We establish a fixed point theorem for a Lie group of isometries acting on a Riemannian manifold with nonnegative curvature.     

A general multi-valued hybrid fixed point theorem and perturbed differential inclusions

Combining three basic multi-valued versions of Banach, Schauder and Tarski fixed point theorems, a general hybrid fixed point theorem for multi-valued mappings in Banach spaces is proved via measure of noncompactness and it is further applied to perturbed differential inclusions for proving the existence results under mixed Lipschitz, compactness and monotone conditions.     

A Schauder-type fixed point theorem

In this brief note we study Schauder's second fixed point theorem in the space $(\mathit{BC},6\cdot 6)$ of bounded continuous functions $\varphi :[0,\infty )\to {\Re }^n$ with a view to reducing the requirement that there is a compact map to the requirement that the map is locally equicontinuous. Several examples are given, both motivating and applying the theory.     

A Mönch type fixed point theorem under the interior condition

In this paper we show that the well-known Mönch fixed point theorem for non-self mappings remains valid if we replace the Leray-Schauder boundary condition by the interior condition. As a consequence, we obtain a partial generalization of Petryshyn's result for nonexpansive mappings.     

Common fixed point theorem for hybrid generalized multi-valued contraction mappings

In this paper, we introduce the notion of a hybrid generalized multi-valued contraction mapping and establish the common fixed point theorem for this mapping. Our results generalize, unify, extend and complement several common fixed point theorems of many authors in the literature.     

A fixed point theorem equivalent to the Fan-Knaster-Kuratowski-Mazurkiewicz theorem

In this note we prove a fixed point theorem and show that this fixed point theorem is equivalent to a recent generalization of the Knaster-Kuratowski-Mazurkiewicz theorem by Ky Fan.     

Common fixed point theorem for noncommuting mappings satisfying a generalized asymptotically nonexpansive condition

We present a common fixed point theorem for generalized asymptotically nonexpansive and noncommuting mappings in normed linear spaces.      

A fixed point theorem in hyperconvex spaces

In this article we prove a new fixed point theorem for hyperconvex metric spaces. The significance of our result will be clarified by suitable examples and a comparison with earlier fixed point theorems for hyperconvex spaces. In particular, we prove that the space \Bbb Rⁿ\Bbb R^n with the metric "river" or with the radial metric is hyperconvex.     

A fixed point theorem for the pseudo-circle

Let f:C→C be a self-map of the pseudo-circle C. Suppose that C is embedded into an annulus A, so that it separates the two components of the boundary of A. Let F:A→A be an extension of f to A (i.e. F|C=f). If F is of degree d then f has at least |d−1| fixed points. This result generalizes to all plane separating circle-like continua.     

A fixed point theorem for discontinuous functions

Any function from a non-empty polytope into itself that is locally gross direction preserving is shown to have the fixed point property. Brouwer's fixed point theorem for continuous functions is a special case. We discuss the application of the result in the area of non-cooperative game theory.     

A random fixed point theorem for multifunctions

A Class of multifunctions is introduced and a random fixed point theorem for pairs of measurable multifunctions belonging to this class is proved. The result is then used to study the existence of solutions for a class of random operator equations     

A fixed point theorem in metric spaces

We discuss a fixed point theorem for a function f mapping a complete metric space X into itself. For all x ? X{x \in X} the iterates of f(x) are shown to converge to x_* = f(x_*){{x_{\star} = f(x_{\star})}} and an explicit estimate of the convergence rate is given.     

On a fixed point theorem of Kirk

W.A. Kirk [J. Math. Anal. Appl. 277 (2003) 645-650] first introduced the notion of asymptotic contractions and proved the fixed point theorem for this class of mappings. In this note we present a new short and simple proof of Kirk's theorem.     

A surjection theorem and a fixed point theorem for a class of positive operators

This paper is concerned with α-convex operators on ordered Banach spaces. A surjection theorem for 1-convex operators in order intervals is established by means of the properties of cone and monotone iterative technique. It is assumed that 1-convex operator A is increasing and satisfies Ay−Ax?M(y−x) for θ?x?y?v₀, where θ denotes the zero element and v₀ is a constant. Moreover, we prove a fixed point theorem for -convex operators by using fixed point theorem of cone expansion. In the end, we apply the fixed point theorem to certain integral equations.     

A fixed point theorem for a class of Sobolev maps

We prove an analog of the Brouwer fixed point theorem for a map whose differential and adjoint are integrable with exponents n−1 and n/(n−1) respectively. Here Ω is a convex bounded open subset of Rⁿ.

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