Generally we use definitions and notation as in [D]. In particular, (W,S) is a finitely generated Coxeter system, C is a building with Weyl group W , |C| is the Davis realization of C. We will, however, confuse the Coxeter group and its abstract Coxeter complex, denoting both by W ; in particular, |W | denotes the Davis complex. The W -valued distance in C will be denoted δC , while δ will be t...

Let (X,1) be a partially ordered set and d be a metric on X such that (X, d) is a complete metric space. Let F : X ×X Ã X be a mixed monotone set valued mapping. We obtain sufficient conditions for the existence of a coupled fixed point of F.

After the definition of the concept of fuzzy metric space by some authors 1–3 , the fixed point theory on these spaces has been developing see, e.g., 4–9 . Generally, this theory on fuzzy metric space is done for contractive or contractive-type mappings see 2, 10–13 and references therein . In this paper we introduce the concept of fuzzy order ψ-contractive mappings and give two fixed point the...

Generally we use definitions and notation as in [D]. In particular, (W,S) is a finitely generated Coxeter system, C is a building with Weyl group W , |C| is the Davis realization of C. We will, however, confuse the Coxeter group and its abstract Coxeter complex, denoting both by W ; in particular, |W | denotes the Davis complex. The W -valued distance in C will be denoted δC , while δ will be t...

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.

Generally we use definitions and notation as in [D]. In particular, (W,S) is a finitely generated Coxeter system, C is a building with Weyl group W , |C| is the Davis realization of C. We will, however, confuse the Coxeter group and its abstract Coxeter complex, denoting both by W ; in particular, |W | denotes the Davis complex. The W -valued distance in C will be denoted δC , while δ will be t...

‎In this study‎, ‎we investigate topological properties of fuzzy strong‎ b-metric spaces defined in [13]‎. ‎Firstly‎, ‎we prove Baire's theorem for‎ ‎these spaces‎. ‎Then we define the product of two fuzzy strong b-metric spaces‎ ‎defined with same continuous t-norms and show that $X_{1}times X_{2}$ is a‎ ‎complete fuzzy strong b-metric space if and only if $X_{1}$ and $X_{2}$ are‎ ‎complete fu...

Let X, Y be complete metric spaces and E, F be Banach spaces. A bijective linear operator from a space of E-valued functions on X to a space of F -valued functions on Y is said to be biseparating if f and g are disjoint if and only if Tf and Tg are disjoint. We introduce the class of generalized Lipschitz spaces, which includes as special cases the classes of Lipschitz, little Lipschitz and uni...

Recall that a conformal 4-manifold is called self-dual if its Weyl curvature, considered as a bundle valued 2-form, is in the +1 eigenspace of the Hodge star-operator [1]. Due to Schoen’s proof [19] of the Yamabe conjecture it is known that within any conformal class on a compact manifold is a metric whose scalar curvature is constant and the sign of this constant is a conformal invariant. The ...