A subset A of a metric space (X, d) is central iff for every Katětov map f : X → R upper bounded by the diameter of X and any finite subset B of X there is x ∈ X such that f(a) = d(x, a) for each a ∈ A ∪ B. Central subsets of the Urysohn universal space U (see introduction) are studied. It is proved that a metric space X is isometrically embeddable into U as a central set iff X has the collinea...

In this paper, we shall establish some fixed point theorems for mappings with the contractive  condition of integrable type on complete intuitionistic fuzzy metric spaces $(X, M,N,*,lozenge)$. We also use Lebesgue-integrable mapping to obtain new results. Akram, Zafar, and Siddiqui introduced the notion of $A$-contraction mapping on metric space. In this paper by using the main idea of the work...

In this paper we prove an analogue of Banach and Kannan fixed point theorems by generalizing the Lipschitz constat $k$, in generalized Lipschitz mapping on cone metric space over Banach algebra, which are answers for the open problems proposed by Sastry et al, [K. P. R. Sastry, G. A. Naidu, T. Bakeshie, Fixed point theorems in cone metric spaces with Banach algebra cones, Int. J. of Math. Sci. ...

In this paper, tripled coincidence points of mappings satisfying  $psi$-contractive conditions in the framework of partially ordered $G_b$-metric spaces are obtained. Our results extend the results of Aydi et al. [H. Aydi, E. Karapinar and W. Shatanawi, Tripled fixed point results in generalized metric space, J. Applied Math., Volume 2012, Article ID 314279, 10 pages]. Moreover, some examples o...

In this paper, we present fixed point theorems for contraction mappings in a generalization of an extended $b$-metric space where the product Lipschitz constant and functions underlying limit are bounded by one sequences orbit. Futhermore, prove results which involves $b$-comparison functions.

The focus of this paper is to acquaint with generalized condition (B) in a quasi-partial b-metric space and establish coincidence common fixed point theorems for weakly compatible pairs mapping. Additionally, the background space, outcomes obtained are exemplified prove existence uniqueness point.

and Applied Analysis 3 effectively larger than that of the ordinary conemetric spaces. That is, every cone metric space is a cone b-metric space, but the converse need not be true. The following examples show the above remarks. Example 7. Let X = {−1, 0, 1}, E = R, andP = {(x, y) : x ≥ 0, y ≥ 0}. Define d : X × X → P by d(x, y) = d(y, x) for all x, y ∈ X, d(x, x) = θ, x ∈ X, and d(−1, 0) = (3, ...

We consider the concept of Ω-distance on a complete partially ordered G-metric space and prove some common fixed point theorems.

In this paper, we prove some common fixed point results for pair of rational type of contractive mappings in the setting of complex valued b-metric spaces. Our results extend, generalize and improve the corresponding results of A. K .Dubey’ [48]. Key word: Complex valued b-metric space; common fixed point; Rational expression type of contractive mappings.

Clearly, the metric space ( ,d) is complete. In this paper, we use the concept of porosity [1, 2, 3, 4, 5, 6] which we now recall. Let (Y ,ρ) be a complete metric space. We denote by B(y,r) the closed ball of center y ∈ Y and radius r > 0. A subset E ⊂ Y is called porous in (Y ,ρ) if there exist α ∈ (0,1) and r0 > 0 such that for each r ∈ (0,r0] and each y ∈ Y , there exists z ∈ Y for which B(z...