It is well known that the classical contraction mapping principle of Banach is a fundamental result in fixed point theory. Several authors have obtained various extensions and generalizations of Banach’s theorems by considering contractive mappings on different metric spaces. Huang and Zhang [1] have replaced real numbers by ordering Banach space and have defined a cone metric space. They have ...

Lenses and quasi-lenses on a space X form models of erratic non-determinism. When is equipped with quasi-metric d, there are natural quasi-metrics dP dPa the X, which resemble Pompeiu-Hausdorff metric (and contain it as subcase when d metric), tightly connected to Kantorovich-Rubinstein dKR dKRa Parts I, II III, through an isomorphism between so-called discrete normalized forks. We show that co...

The existing literature of fixed point theory contains many results enunciating fixed point theorems for self-mappings in metric and Banach spaces. Recently, Huang and Zhang [4] introduced the concept of cone metric spaces which generalized the concept of the metric spaces, replacing the set of real numbers by an ordered Banach space, and obtained some fixed point theorems for mapping satisfyin...

in this paper, we prove some coupled coincidence point theorems for mappings with the mixedmonotone property and obtain the uniqueness of this coincidence point. then we providing useful examples in nash equilibrium.

In this paper, an idea of generalized fuzzy c-distance in fuzzy cone metric space is introduced. A common fixed point theorem is established for a pair of self mappings in fuzzy cone metric spaces by using the concept of generalized fuzzy c-distance. 2010 AMS Classification: : 54A40, 03E72

In this work, we define a weaker Meir–Keeler type function ψ : int P ∪ {0} → int P ∪ {0} in a cone metric space, and under this weaker Meir–Keeler type function, we show the common fixed point theorems of four single-valued functions in cone metric spaces. © 2010 Elsevier Ltd. All rights reserved.

It was shown that quantum metric fluctuations smear out the singularities of Green’s functions on the light cone [1], but it does not remove other ultraviolet divergences of quantum field theory. We have proved that the quantum field theory in Krein space, i.e. indefinite metric quantization, removes all divergences of quantum field theory with exception of the light cone singularity [2, 3]. In...

In this paper, we prove that if f is a contractive closed-valued correspondence on a cone metric space (X, d) and there is a contractive orbit {xn} for f at x0 ∈ X such that both {xni} and {xni+1} converge for some subsequence {xni} of {xn}, then f has a fixed point, which generalizes a fixed point theorem for contractive closed-valued correspondences from metric spaces to cone metric spaces.

In [15] M. Schellekens introduced the complexity (quasi-metric) space as a part of the research in Theoretical Computer Science and Topology, with applications to the complexity analysis of algorithms. Later on, S. Romaguera and M. Schellekens ([13]) introduced the so-called dual complexity (quasi-metric) space and established several quasi-metric properties of the complexity space via the anal...

We give a new notion of angle in general metric spaces; more precisely, given a triple a points p, x, q in a metric space (X, d), we introduce the notion of angle cone ∠pxq as being an interval ∠pxq := [∠pxq,∠ + pxq], where the quantities ∠ ± pxq are defined in terms of the distance functions from p and q via a duality construction of differentials and gradients holding for locally Lipschitz fu...