This paper models ion-acoustic shock waves in a magnetized, dissipative plasma containing inertial nondegenerate positive and negative ions together with inertialess relativistically degenerate electrons and positrons. Starting from normalized fluid equations, the authors apply reductive perturbation theory to derive a Korteweg-de Vries-Burgers equation for weakly nonlinear propagation. Its travelling-wave solution supports only positive-potential, compressive shocks for both acoustic modes considered. Parameter scans show that ion-density ratios, electron and positron fractions, the positive-to-negative ion temperature ratio, magnetic-field strength, and parallel and perpendicular kinematic and bulk viscosities alter shock amplitude and steepness. In the reported regime, stronger dissipation enhances the oscillatory shock structure, while larger temperature and magnetic-field parameters raise the shock potential. The evolution equation is also recast as a planar dynamical system; its equilibria include a saddle at the origin and a centre at the nonzero fixed point for the selected parameters. The model targets nonlinear electrostatic structures in dense environments such as white dwarfs and neutron stars.
- Formulated a four-species magnetized plasma model with nondegenerate pair ions and relativistically degenerate electron-positron populations.
- Derived the Korteweg-de Vries-Burgers evolution equation and its shock solution by reductive perturbation theory.
- Established positive-potential compressive ion-acoustic shocks for both acoustic modes in the studied regime.
- Quantified how density ratios, temperature ratio, magnetic field, and viscous dissipation control shock structure.
- Recast the evolution equation as a planar dynamical system and classified its saddle and centre equilibria.