LAUSR

This article examines the essential phenomena of nonlinear ion-acoustic waves (IAWs) in the unmagnetized relativistic collisionless plasmas by considering generalized distributed electrons, Boltzmann distributed positrons, and relativistic ions having kinematic viscosity. The nonlinear electrostatic IA shock and solitary wave dynamics are conducted by new nonlinear evolution equations, such as Korteweg-de Vries (KdV)–Burgers-type Schamel equation and the well-known KdV-type Schamel equation, respectively, due to the involvement of superthermal electrons, having trapping efficiency and kinematic viscosity of ions. It is first time reported that the nonlinear IAWs are supported by only positive polarity shock structures and solitons for superthermal electrons, having trapping efficiency with and without the influence of kinematic viscosity of ions, respectively, in the relativistic plasmas.