Are fixed point theorems in G-metric spaces an authentic generalization of their classical counterparts?

Abstract

[eng] Are fixed point theorems in G-metric spaces an authentic generalization of their classical counterparts?\thanks{J.J. Mi\~nana and O. Valero acknowledge financial support from the Spanish Ministry of Economy and Competitiveness under Grants TIN2016-81731-REDT (LODISCO II) and AEI/FEDER, UE funds, by Programa Operatiu FEDER 2014-2020 de les Illes Balears, by project ref. PROCOE/4/2017 (Direcci\'{o} General d'Innovaci\'{o} i Recerca, Govern de les Illes Balears), and by project ROBINS. The latter has received research funding from the EU H2020 framework under GA 779776. This publication reflects only the authors views and the European Union is not liable for any use that may be made of the information contained therein. A. Estevan acknowledges financial support from the Ministry of Economy and Competitiveness of Spain under grants MTM2015-63608-P (MINECO/FEDER) and ECO2015-65031 as well as from the Basque Government under grant IT974-16.