Ultra-low-frequency electrostatic and electromagnetic modes in self-gravitating magnetized dusty plasmas
Department of Physics, Jahangirnagar University, Savar, Dhaka, Bangladesh
2 University of Cambridge, Cavendish Laboratory, Cambridge CB3 OHE, UK
Published online: 15 September 2000
A theoretical investigation has been made of ultra-low-frequency dust-electrostatic and dust-electromagnetic modes, propagating perpendicular to the external magnetic field, in a self-gravitating, warm, magnetized, two fluid dusty plasma system. It has been shown that the effects of self-gravitational field and dust thermal pressure significantly modify the dispersion properties of these ultra-low-frequency dust-modes. It is also found that under certain conditions, the self-gravitational effect can destabilize these ultra-low-frequency dust-electrostatic and dust-electromagnetic modes. However, the effects of the external magnetic field and dust and ion thermal pressures are found to play stabilizing role, i.e., these effects make these modes stable and counter the gravitational condensation of the dust grains. The implications of these results to some space and astrophysical dusty plasma systems, especially, to planetary ring-systems and cometary tails, are briefly mentioned.
PACS: 52.35.Fp – Electrostatic waves and oscillations (e.g., ion-acoustic waves) / 52.35.Lv – Other linear waves / 52.25.Zb – Dusty plasmas; plasma crystals
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000