İshak Altun - Academia.edu (original) (raw)

Papers by İshak Altun

Proceedings of International Mathematical Sciences

We introduce Suzuki type P-contractive mappings by taking into account the concepts of contractiv... more We introduce Suzuki type P-contractive mappings by taking into account the concepts of contractive, P-contractive, and Suzuki type contractive mappings. Then, for such mappings on compact metric spaces, we present a fixed point theorem that is more general than the well-known Edelstein fixed point theorem.

Hacettepe Journal of Mathematics and Statistics, 2017

Recently, Wardowski in [Fixed points of a new type of contractive mappings in complete metric spa... more Recently, Wardowski in [Fixed points of a new type of contractive mappings in complete metric spaces, Fixed Point Theory Appl. 2012] introduced the concept of F-contraction on complete metric space which is a proper generalization of Banach contraction principle. In the present paper, we proved a related fixed point theorem with F-contraction mappings on two complete metric spaces.

TURKISH JOURNAL OF MATHEMATICS, 2016

In this work, inspired by the recent technique of Jleli and Samet, we give a new generalization o... more In this work, inspired by the recent technique of Jleli and Samet, we give a new generalization of the wellknown Mizoguchi-Takahashi fixed point theorem, which is the closest answer to Reich's conjecture about the existence of fixed points of multivalued mappings on complete metric spaces. We also provide a nontrivial example showing that our result is a proper generalization of the Mizoguchi-Takahashi result.

Hacettepe Journal of Mathematics and Statistics, 2016

In his recent paper, Wardowski [16] introduced the concept of Fcontraction, which is a proper gen... more In his recent paper, Wardowski [16] introduced the concept of Fcontraction, which is a proper generalization of ordinary contraction on a complete metric space. Then, some generalizations of F-contractions including multivalued case are obtained in [2, 4, 7, 13]. In this paper, by considering both F-contractions and fixed point result on ordered metric spaces, we introduce a new concept of ordered F-contraction on ordered metric space. Then, we give a fixed point theorem for such mapping. To support our result, we give an example showing that our main theorem is applicable, but both results of Ran and Reurings [12] and Wardowski [16] are not.

Complex Variables and Elliptic Equations, 2006

... 02781070500333541 İshak Altun a * , Kerİm Koca a & Bİnalİ Musayev a pages 181-195. ... Lö... more ... 02781070500333541 İshak Altun a * , Kerİm Koca a & Bİnalİ Musayev a pages 181-195. ... Lösung nichtlinearer partieller Differentialgleichungssysteme erster Ordnung in der Ebene durch Verwendung einer komplexen Normalform. Mathematische Nachrichten , 75: 283–298. ...

Proceedings of International Mathematical Sciences

We introduce Suzuki type P-contractive mappings by taking into account the concepts of contractiv... more We introduce Suzuki type P-contractive mappings by taking into account the concepts of contractive, P-contractive, and Suzuki type contractive mappings. Then, for such mappings on compact metric spaces, we present a fixed point theorem that is more general than the well-known Edelstein fixed point theorem.

Hacettepe Journal of Mathematics and Statistics, 2017

Recently, Wardowski in [Fixed points of a new type of contractive mappings in complete metric spa... more Recently, Wardowski in [Fixed points of a new type of contractive mappings in complete metric spaces, Fixed Point Theory Appl. 2012] introduced the concept of F-contraction on complete metric space which is a proper generalization of Banach contraction principle. In the present paper, we proved a related fixed point theorem with F-contraction mappings on two complete metric spaces.

TURKISH JOURNAL OF MATHEMATICS, 2016

In this work, inspired by the recent technique of Jleli and Samet, we give a new generalization o... more In this work, inspired by the recent technique of Jleli and Samet, we give a new generalization of the wellknown Mizoguchi-Takahashi fixed point theorem, which is the closest answer to Reich's conjecture about the existence of fixed points of multivalued mappings on complete metric spaces. We also provide a nontrivial example showing that our result is a proper generalization of the Mizoguchi-Takahashi result.

Hacettepe Journal of Mathematics and Statistics, 2016

In his recent paper, Wardowski [16] introduced the concept of Fcontraction, which is a proper gen... more In his recent paper, Wardowski [16] introduced the concept of Fcontraction, which is a proper generalization of ordinary contraction on a complete metric space. Then, some generalizations of F-contractions including multivalued case are obtained in [2, 4, 7, 13]. In this paper, by considering both F-contractions and fixed point result on ordered metric spaces, we introduce a new concept of ordered F-contraction on ordered metric space. Then, we give a fixed point theorem for such mapping. To support our result, we give an example showing that our main theorem is applicable, but both results of Ran and Reurings [12] and Wardowski [16] are not.

Complex Variables and Elliptic Equations, 2006

... 02781070500333541 İshak Altun a * , Kerİm Koca a & Bİnalİ Musayev a pages 181-195. ... Lö... more ... 02781070500333541 İshak Altun a * , Kerİm Koca a & Bİnalİ Musayev a pages 181-195. ... Lösung nichtlinearer partieller Differentialgleichungssysteme erster Ordnung in der Ebene durch Verwendung einer komplexen Normalform. Mathematische Nachrichten , 75: 283–298. ...