Propagation of Ion Solitary Pulses in Dense Astrophysical Electron-Positron-Ion Magnetoplasmas

In this paper,we theoretically investigate the existence and propagation of low amplitude nonlinear ion waves in a dense plasma under the influence of a strong magnetic field.The plasma consists of ultra-relativistic and degenerate electrons and positrons and non-degenerate cold ions.Firstly,the appearance of two distinct linear modes and their evolution is studied by deriving a dispersion equation with the aid of Fourier analysis.Secondly,the dynamics of low amplitude ion solitary structures is investigated via a Korteweg-de Vries equation derived by employing a reductive perturbation method.The effects of various plasma parameters like positron concentration,strength of magnetic field,obliqueness of field,etc.,are discussed in detail.At the end,analytical results are supplemented through numerical analysis by using typical representative parameters consistent with degenerate and ultra-relativistic magnetoplasmas of astrophysical regimes.