Fixed point theorems for nonexpansive mappings in modular spaces

Poom Kumam


Address.
  Department of Mathematics, Faculty of Science, King Mongkut's University of Technology Thonburi Bangkok 10140, Thailand
 

E-mail. pooom.kum@kmutt.ac.th

Abstract.
In this paper, we extend several concepts from geometry of Banach spaces to modular spaces. With a careful generalization, we can cover all corresponding results in the former setting. Main result we prove says that if $\rho$ is a convex, $\rho$-complete modular space satisfying the Fatou property and $\rho_r$-uniformly convex for all $r>0$, C a convex, $\rho$-closed, $\rho$-bounded subset of $X_\rho$, $T:C\rightarrow C$ a $\rho$-nonexpansive mapping, then $T$ has a fixed point.

AMSclassification. 46B20, 46E30, 47H10.

Keywords.  Fixed point, modular spaces, $\rho$-nonexpansive mapping, $\rho$-normal structure, $\rho$-uniform normal structure, $\rho_r$-uniformly convex.