Dust-ion-acoustic supersolitons in dusty plasmas with nonthermal electrons.

Supersolitons are a recent addition to the literature on large-amplitude solitary waves in multispecies plasmas. They are distinguished from the usual solitons by their associated electric field profiles which are inherently distinct from traditional bipolar structures. In this paper, dust-ion-acoustic modes in a dusty plasma with stationary negative dust, cold fluid protons, and nonthermal electrons are investigated through a Sagdeev pseudopotential approach to see where supersolitons fit between ranges of ordinary solitons and double layers, as supersolitons always have finite amplitudes.

Head-on collisions of electrostatic solitons in nonthermal plasmas.

In contrast to overtaking interactions, head-on collisions between two electrostatic solitons can be dealt with only by use of an approximate method, which limits the range of validity but offers valuable insights. Treatments in the plasma physics literature all use assumptions in the stretching of space and time and in the expansion of the dependent variables that are seldom, if ever, discussed. All models force a separability to lowest order, corresponding to two linear waves with opposite but equally large velocities.

Electrostatic modes in dusty plasmas with continuous size distributions.

When the dust plasma frequency, and hence the dust-acoustic velocity is computed for a dusty plasma containing charged grains with individual identities, three possibilities occur in a natural way. One form is based on the average over all dust grains of the ratio of the square of charge to mass, whereas a second one uses the average charge and the average mass. The difference between the two gives rise to a dust distribution mode.

Static configurations of gravitating dusty plasmas.

Plasma and dust are key ingredients of the universe, and in larger astrophysical systems the gravitational and electrostatic forces can become comparable, thus prompting a careful revision of stationary configurations of self-gravitating dusty plasmas. An overview of some physically acceptable models is given, with applications to relevant structures in space and astrophysical plasmas. For those cases where explicit solutions can be obtained, the scales over which the system is inhomogeneous are of the order of the Jeans lengths, determined in the usual way by studying local perturbations of a uniform equilibrium.

Oblique electrostatic modes in self-gravitating dusty plasmas.

The propagation of oblique and perpendicular electrostatic modes in dusty self-gravitational magnetized plasmas is treated with due care for the small gravitational effects between charged dust particles and for the correct balance between electrostatic and gravitational forces. At purely oblique propagation, generalizations of the dust-cyclotron and dust-acoustic modes are found, where the latter can be subject to a Jeans instability. For strictly perpendicular propagation, only a mixed dust-acoustic and dust lower-hybrid mode occur at low frequencies.