Dust-acoustic solitary waves and double layers in dusty plasma with variable dust charge and two-temperature ions

With two-temperature ions in dusty plasma, the effects of variable dust cha rge on small-amplitude dust-acoustic solitons and large-amplitude dust-acou stic solitary waves are investigated. It is found that both compressive and rarefactive solitons (and solitary waves), as well as double layers, exist . The introduced small, but finite, number density of the lower temperature ions provides the possibility of the coexistence of large-amplitude rarefa ctive with compressive dust-density solitary waves. The amplitudes of those dust-density solitary waves become smaller and the regime of Mach number i s extended wider for the variable dust charge situation compared to the con stant dust charge situation. (C) 1999 American Institute of Physics. [S1070 -664X(99)02010-8].