Browsing by Author "Radenovic, Stojan"

Now showing 1 - 4 of 4

Citation - WoS: 14
Citation - Scopus: 19
Common Fixed Points of Weak Contractions in Cone Metric Spaces
(Hindawi Publishing Corporation, 2012) Ding, Hui-Sheng; Kadelburg, Zoran; Karapinar, Erdal; Radenovic, Stojan; Mathematics
Results on common fixed points of mappings in cone metric spaces under weak contractive conditions (B. S. Choudhury and N. Metiya (2010)) are unified and generalized. Also, cone metric versions of some other related results on weak contractions are proved. Examples show that our results are different than the existing ones.
Citation - WoS: 10
Citation - Scopus: 9
Some Inevitable Remarks on "tripled Fixed Point Theorems for Mixed Monotone Kannan Type Contractive Mappings"
(Hindawi Publishing Corp, 2014) Alsulami, Hamed H.; Roldan-Lopez-de-Hierro, Antonio-Francisco; Karapinar, Erdal; Radenovic, Stojan; Mathematics
We advise that the proof of Theorem 12 given by Borcut et al. (2014) is not correct, and it cannot be corrected using the same technique. Furthermore, we present some similar results as an approximation to the opened question if that statement is valid.
Citation - WoS: 21
Citation - Scopus: 18
Tripled Coincidence Fixed Point Results for Boyd-Wong and Matkowski Type Contractions
(Springer-verlag Italia Srl, 2013) Aydi, Hassen; Karapinar, Erdal; Radenovic, Stojan; Mathematics
In this paper, we establish tripled coincidence and common tripled fixed point theorems of Boyd-Wong and Matkowski type contractions. The presented theorems generalize and extend several well known comparable results in the literature, in particular the results of Samet and Vetro (for tripled case) [Ann Funct Anal 1(2):46-56, 2010]. We illustrate our obtained results by some examples.
Citation - WoS: 27
Citation - Scopus: 34
Θ-Metric Space: a Generalization
(Hindawi Ltd, 2013) Khojasteh, Farshid; Karapınar, Erdal; Karapinar, Erdal; Radenovic, Stojan; Karapınar, Erdal; Mathematics; Mathematics
We introduce the notion of theta-metric as a generalization of a metric by replacing the triangle inequality with a more generalized inequality. We investigate the topology of the spaces induced by a theta-metric and present some essential properties of it. Further, we give characterization of well-known fixed point theorems, such as the Banach and Caristi types in the context of such spaces.