Nonlinear Isothermal Acoustic Wave Propagation in Quantum Degenerate Electron–Positron–Ion Plasmas

Nonlinear propagation of quantum degenerate positron acoustic waves (PAWs) in dense quantum collisionless unmagnetized plasma at nonzero temperature is considered. The plasma constituents are hot electrons, hot and cold positrons, and positive immobile ions. The equations of state for hot electrons and positrons, with quantum hydrodynamic model, are used to drive the evolution equation of the system. A Korteweg-de Vries equation is derived using the reductive perturbation method. Analytically, the influence of the chemical potential and the quantum degenerate effects on the solitary structures is taken into account. These investigations can be helpful in understanding the nonlinear features of PAWs in various astrophysical plasmas, such as planetary interiors and compact astrophysical objects.