Dust ion acoustic solitons in a plasma with kappa-distributed electrons

Dust ion acoustic solitons in an unmagnetized dusty plasma comprising cold dust particles, adiabatic fluid ions, and electrons satisfying a $\kappa$ distribution are investigated using both small amplitude and arbitrary amplitude techniques. Their existence domain is discussed in the parameter space of Mach number $M$ and electron density fraction $f$ over a wide range of values of $\kappa$ . For all $\kappa >3/2$ , including the Maxwellian distribution, negative dust supports solitons of both polarities over a range in $f$ . In that region of parameter space solitary structures of finite amplitude can be obtained even at the lowest Mach number, the acoustic speed, for all $\kappa$ . These cannot be found from small amplitude theories. This surprising behavior is investigated, and it is shown that $f_c$ , the value of $f$ at which the KdV coefficient $A$ vanishes, plays a critical role. In the presence of positive dust, only positive potential solitons are found.