Mihai Postolache

Coupled fixed point results for (ψ,φ)-weakly contractive mappings in ordered G-metric spaces

In this paper, we establish coupled coincidence and common coupled fixed point theorems for (@j,@f)-weakly contractive mappings in ordered G-metric spaces. Presented theorems extend, generalize and improve many existing results in the literature. An example is given.

Tripled coincidence point theorems for weak φ-contractions in partially ordered metric spaces

In this article, we present tripled coincidence point theorems for F: X3 → X and g: X → X satisfying weak φ-contractions in partially ordered metric spaces. We also provide nontrivial examples to illustrate our results and new concepts presented herein. Our results unify, generalize and complement various known comparable results from the current literature, Berinde and Borcut and Abbas et al.

A generalized weak contraction principle with applications to coupled coincidence point problems

In this paper we establish some coincidence point results for generalized weak contractions with discontinuous control functions. The theorems are proved in metric spaces with a partial order. Our theorems extend several existing results in the current literature. We also discuss several corollaries and give illustrative examples. We apply our result to obtain some coupled coincidence point results which effectively generalize a number of established results.MSC:54H10, 54H25.

Strong convergence of a self-adaptive method for the split feasibility problem

Self-adaptive methods which permit step-sizes being selected self-adaptively are effective methods for solving some important problems, e.g., variational inequality problems. We devote this paper to developing and improving the self-adaptive methods for solving the split feasibility problem. A new improved self-adaptive method is introduced for solving the split feasibility problem. As a special case, the minimum norm solution of the split feasibility problem can be approached iteratively.MSC:47J25, 47J20, 49N45, 65J15.

Coincidence and fixed point results for generalized weak contractions in the sense of Berinde on partial metric spaces

In this paper, we introduce the notion of a generalized (ϕ,L)-weak contraction and we prove some common fixed point results for self-mappings T and S and some fixed point results for a single mapping T by using a (c)-comparison function and a comparison function in the sense of Berinde in a partial metric space. Also, we introduce an example to support the useability of our results.MSC:47H10, 54H25.

Common fixed point theorems for dominating and weak annihilator mappings in ordered metric spaces

Very recently, Haghi et al. (Topol. Appl. 160:450-454, 2013) proved that some fixed point theorems in partial metric spaces can be obtained from metric spaces. In this paper, we prove some common fixed point theorems for four mappings f, g, S and T satisfying a nonlinear contraction in ordered metric spaces, where the mappings f and g are dominating and weak annihilators of the mappings T and S, respectively. We utilize the techniques of Haghi et al. to derive our main result, which is a generalization of the result of Shobkolaei et al. (Appl. Math. Comput. 219:443-452, 2012). Also, we introduce an example to support the usability of our results.MSC:54H25, 47H10.

Common fixed point results for mappings under nonlinear contraction of cyclic form in ordered metric spaces

In this paper, we introduce the notion of a cyclic (ψ,A,B)-contraction for the pair (f,T) of self-mappings on the set X. We utilize our definition to introduce some common fixed point theorems for the two mappings f and T under a set of conditions. Also, we introduce an example to support the validity of our results. As application of our results, we derive some common fixed point theorems of integral type.MSC:54H25, 47H10.

Some Fixed-Point Results for a G-Weak Contraction in G-Metric Spaces

We introduce the concepts of a -weak contraction mapping of types and and we establish some fixed point theorems for a -weak contraction mapping of types and in complete -metric spaces. Our results generalize several well-known comparable results in the literature.

Fixed point theorem for weakly Chatterjea-type cyclic contractions

In this article, we introduce the notion of a Chatterjea-type cyclic weakly contraction and derive the existence of a fixed point for such mappings in the setup of complete metric spaces. Our result extends and improves some fixed point theorems in the literature. Example is given to support the usability of the result.MSC:41A50, 47H10, 54H25.

Stability results for Jungck-type iterative processes in convex metric spaces

Abstract In this paper, we obtain some stability results in complete convex metric spaces for nonselfmappings satisfying certain general contractivity condition. We prove our results for Jungck–Mann and Jungck–Ishikawa iterations. Our results extend several stability results in the literature.