the aim of this paper is to prove some common fixed point theorems for four  mappings satisfying $(psi,varphi)$-weak contractions involving rational expressions in ordered partial metric spaces. our results extend, generalize and improve some well-known results in the literature. also, we give two examples to illustrate our results.

in this paper, we study the existence of coupled coincidence andcoupled common fixed points for single-valued and fuzzy mappingsunder a contractive condition in metric space. presented theoremsextend and improve the main results of abbas and$acute{c}$iri$acute{c}$ {itshape et al.} [m. abbas, l.$acute{c}$iri$acute{c}$, {itshape et al.}, coupled coincidenceand common fixed point theorems for hybr...

in this paper, we prove some approximate fixed point results for proximinal valued $beta$-contractive multifunctions on metric spaces. we show that our results generalize some old fixed point results in the literature.

in this paper, a concept of generalized weakly contraction mappings in partially ordered fuzzy metric spaces is introduced and  coincidence point  theorems on partially ordered fuzzy metric spaces are proved. also, as the corollary of these theorems, some common fixed point theorems on partially ordered fuzzy metric spaces are presented.

The purpose of this paper is to draw attention to existential fixed-point logic. Among other things, we show that: (1) If a structure A satisfies an existential fixed-point formula φ, then A has a finite subset F such that every structure B with A |F = B |F satisfies φ. (2) Using existential fixed-point logic instead of first-order logic removes the expressivity hypothesis in Cook's completenes...

Jointly with H.-P. Künzi we started investigating a concept of spherical completeness in ultra-quasipseudometric spaces which we called q-spherical completeness. In this article we study fixed point theorems in a space X endowed with a non-Archimedean asymmetric norm structure. Here we extend certain results of Petalas and Vidalis and Kirk and Shahzad.

This paper is concerned with dynamics in general ultrametric spaces. We prove the Fixed Point Theorem, the Stability Theorem, the Common Point Theorem, the Local Fixed Point Theorem, the Attractor Theorem and we derive conditions for a mapping to be surjective. We also discuss tightly continuous mappings and prove a theorem about the transfer of the property of principal completeness by a mappi...

In this paper, introducing a contraction principle on generalized metric spaces, a generalization of Banach’s fixed point theorem is obtained under the completeness condition of the space. Moreover, it is established that using such contraction principle completeness of the generalized metric space can be characterized.

Mathematical methods are extensively used in dealing with simulation and approximation problems related to computer science, engineering, physics, many others [...]

The main purpose of this paper is to obtain sufficient conditions for existence of points of coincidence and common fixed points for three self mappings in $b$-metric spaces. Next, we obtain cone $b$-metric version of these results by using a scalarization function. Our results extend and generalize several well known comparable results in the existing literature.