Suppression of the Kelvin-Helmholtz instability due to polarization force in nonuniform magnetized sheared dusty plasmas

The Kelvin-Helmholtz (K-H) instability in a magnetized nonuniform velocity sheared dusty plasma is investigated accounting for the effects of dust polarization force due to inhomogeneity in background plasma number densities. A three-component fluid model for dusty plasma is formulated considering Boltzmann electron/ion fluids and flowing magnetized dust fluids whose dynamics are affected due to the presence of dust polarization force. A dispersion relation for the K-H instability is derived by applying normal mode analysis on the linearized perturbation equations of the system. It is found that the polarization parameter dependent dust acoustic mode significantly modifies the dispersion relation of the K-H instability. The critical shear required to excite the K-H instability (S > S-crit) decreases with an increase in the dust polarization parameter and dust cyclotron frequency. The growth rate of the K-H instability is observed to be suppressed due to the presence of the dust polarization parameter. The results have been discussed for experimental magnetized dusty plasmas, which shows that under considered parametric limits, one cannot ignore the presence of dust polarization force on the excitation of the K-H instability in dusty plasmas. The astrophysical consequences are also discussed in Saturn's E-ring in the limiting case of varying dust grain size.