## Cristian Daniel Alecsa, Adrian Petrusel, On some fixed point theorems for multi-valued operators by altering distance technique

Full Text: PDF
Volume 1, Issue 2, 1 August 2017, Pages 237-251

Abstract. The aim of this paper is to present some sufficient conditions for the existence and uniqueness of fixed points for $(\varphi-\psi)$ type contractive multi-valued operators defined by altering distances. Furthermore, our main result consists of two theorems, one involving the convergence of the Picard successive approximation sequence to a fixed point of the multivalued $\varphi-\psi$ operator, and a theorem concerning a more general form for a fixed point result for this type of mappings.