Coupled fixed points for Chatterjea type maps with the mixed monotone property in partially ordered metric spaces

We apply generalization of Ekeland's variational principle in partially ordered complete metric spaces on sets defined by maps with the mix monotone property to obtain sufficient conditions for the existence of coupled fixed points for Chatterjea type of maps. If in addition every ordered pair of elements from the underlying space, considered as an element of the produced space endowed with the classical sum metric, has an upper or lower bound then the coupled fixed point is unique one.