Notes on some recent papers concerning f-contractions in b-metric spaces

Abstract

In several recent papers, attempts have been made to apply Wardowski's method of F-contractions in order to obtain fixed point results for single and multivalued mappings in b-metric spaces. In this article, it is shown that in most cases the conditions imposed on respective mappings are too strong and that the results can be obtained directly, i.e., without using most of the properties of auxiliary function F.