Common coupled fixed point theorems for $$w^*$$ -compatible mappings without mixed monotone property

Abstract

In this paper, we show that the mixed $$g$$ -monotone property in coupled coincidence point theorems can be replaced by generalized property. Hence, these results can be applied in a much wider class of problems. We also study the condition for the uniqueness of a common coupled fixed point and give some example of nonlinear contraction mappings where the existence of the common coupled fixed point cannot be obtained by the mixed monotone property, but it follows by our results. At the end of this paper, we give an open problems for further investigation.