During last 20 years, an essential part of the theory Hausdorff operators is concentrated on their boundedness real Hardy space

In this paper we prove existence of fixed point theorems for Z-contractive map, Geraghty type contractive map and interpolative Hardy-Rogers type contractive mapping in the setting of SJS- metric spaces with two metrics. Examples are constructed to high light the significance of newly obtained results.

This presentation is in two parts. First, we recall the deenition of two types of asymptotic expansions known as nested form and nested expansions. This theory makes it possible to adapt the asymptotic scale to the function under expansion and is based on the theory of Hardy elds 1]. Next, we suggest a reformulation of nested forms in terms of generalized products called star products, and a pr...

In this article we give a unifying approach to the theory of fundamental sequences and their related Hardy hierarchies of number-theoretic functions and we show the equivalence of the new approach with the classical one. Mathematics Subject Classification: 03D20, 03F15, 03E10.