Common fixed point and common coupled fixed point theorems for weakly monotone mappings

In this paper we have established two common fixed point theorems which are variants of the fixed point theorem of Boyd and Wong [On nonlinear contractions, Proc. Amer. Math. Soc. 20(1969), 458-464]. By applying the newly established fixed point theorems two common coupled fixed point theorems have been proved for a pair of weakly increasing mappings. Examples are given to substantiate our theorems.