Theoretical study of dark solitons in media with competing nonlocal nonlinearities and local quintic nonlinearity

Dark solitons, in a medium with competing nonlocal nonlinearities and local quintic nonlinearity, have been studied analytically in this paper. The phenomenological rectangular profile model for nonlocal response function is considered. The exact conditions for the existence of analytical dark soliton solutions are presented using variational principle. The influence of strengths and degrees of competing nonlocality as well as the strength of quintic locality, on the properties of dark solitons, are discussed.