Nonlinear dust–ion acoustic waves in a dusty plasma with non-extensive electrons and ions

Using the reductive perturbation approach, dust–ion acoustic solitons and double layers (DLs) have been studied in a dust–electron–positron–ion (d-e-p-i) plasma composed of q-distributed electrons and positrons, warm fluid ions, and a fraction of immobile dust grains. Existence domains of either solitary waves or DLs are presented and their parametric dependence determined. It is found that particle non-extensivity, dust concentration and positron concentration may drastically affect these existence domains and may play a key role in defining the polarity of these localized structures. Our results should assist in interpreting the nonlinear structures that may occur in astrophysical environments.