The Role of Positive Dust Charge Fluctuations on High‐Frequency Solitary Waves in a Multicomponent Plasma

The propagation characteristics of high‐frequency dust‐electron‐acoustic solitary waves are theoretically investigated in an unmagnetized, collisionless five‐component plasma comprising inertial cold electrons, Maxwellian‐distributed hot electrons and positrons, stationary ions, and charge‐fluctuating positively charged dust grains. Employing the standard reductive perturbation method, the Korteweg–de Vries equation is derived to describe the nonlinear evolution of dust‐electron‐acoustic waves. A key focus of this study is the dynamic charging of positively charged dust grains and their profound influence on wave propagation. Our analytical and numerical results show that, depending on the critical plasma parameters, the system supports both compressive and rarefactive solitary structures. The effect of fundamental plasma parameters and dust charge fluctuations, such as the hot electron‐to‐positron temperature ratio, the relative number densities of plasma species, and the relative dust grain potential energy, significantly modifies the phase velocity, amplitude, and width of solitary waves. These findings provide valuable insights into the nonlinear electrostatic behaviors of multicomponent plasmas in space and laboratory environments.