*Correspondence: [email protected] Department of Mathematics, Hashemite University, Zarqa, Jordan Abstract In this paper, we prove some quadruple coincidence and quadruple common fixed point theorems for F : X4 → X and g : X → X satisfying (φ –ψ ) contractions in partially ordered G-metric spaces. We illustrate our results based on an example of the main theorems. Also, we deduce quadruple coi...

Copyright q 2011 ChiMing Chen. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We obtain some new fixed point theorems for a ψ, φ-pair Meir-Keeler-type set-valued contraction map in metric spaces. Our main results generalize and i...

Let φ(z) = (φ 1 (z),. .. , φ n (z)) be a holomorphic self-map of U n and ψ(z) a holomorphic function on U n , where U n is the unit polydisk of C n. Let p ≥ 0, q ≥ 0, this paper gives some necessary and sufficient conditions for the weighted composition operator W ψ,φ induced by ψ and φ to be bounded and compact between p-Bloch space B p (U n) and q-Bloch space B q (U n).

Let Φ(t) and Ψ(t) be nonnegative convex functions, and let φ and ψ be the right continuous derivatives of Φ and Ψ, respectively. In this paper, we prove the equivalence of the following three conditions: (i) ‖f∗‖Φ ≤ c‖f‖Ψ, (ii) LΨ ⊆ HΦ and (iii) ∫ t s0 φ(s) s ds ≤ cψ(ct), ∀t > s0, where LΨ and HΦ are the Orlicz martingale spaces. As a corollary, we get a sufficient and necessary condition under...

Here φ and ψ are any schemata and Γ is a (possibly empty) set of schemata. The Deduction Theorem, we shall see, is a very nice feature of an axiomatic system, for it allows one to discover theorems much more readily than ordinarily is possible by building actual proofs. Its true value lies elsewhere than in efficiency, though. At the end of this note we will discuss the importance of the Deduct...

Syntax Throughout this monograph, we provide the definition of the syntax of logics in a more relaxed way. Skipping the syntactic rules for brackets (which can be derived from the precedence order of the operators that will be declared in words), the above inductive definition of propositional formulae over AP can be rewritten as Φ ::= true ∣∣∣ a ∣∣∣ Φ1 ∧Φ2 ∣∣∣ ¬Φ where a ∈ AP. The above can be...

and Applied Analysis 3 Definition 1.10 see 5 . Let X,G be a G-metric space and f, g : X → X be given mappings. We say that f is a generalized weakly G-contraction mapping of type B with respect to g if for all x, y, z ∈ X, the following inequality holds: ψ ( G ( fx, fy, fz )) ≤ ψ ( G ( gx, gx, fy ) G ( gy, gy, fz ) G ( gz, gz, fx ) 3 ) − φGgx, gx, fy, Ggy, gy, fz, Ggz, gz, fx, 1.2

In this paper, we study the following extremal problem and its relevance to the sum of the so-called superoptimal singular values of a matrix function: Given an m × n matrix function Φ, when is there a matrix function Ψ * in the set A n,m k such that Z T trace(Φ(ζ)Ψ * (ζ))dm(ζ) = sup Ψ∈A n,m k ˛ ˛ ˛ ˛ Z T trace(Φ(ζ)Ψ(ζ))dm(ζ) ˛ ˛ ˛ ˛ ? The set A n,m k is defined by A n,m k def = n Ψ ∈ H 1 0 (Mn...

Under conditions of Levinson-Smith type, we prove the existence of a τ -periodic solution for the perturbed generalized Liénard equation u′′ + φ(u, u′)u′ + ψ(u) = ω( t τ , u, u′) with periodic forcing term. Also we deduce sufficient condition for existence of a periodic solution for the equation