Planar and nonplanar ion acoustic shock waves in relativistic degenerate astrophysical electron-positron-ion plasmas

Abstract

We have studied the propagation of ion acoustic shock waves involving planar and non-planar geometries in an unmagnetized plasma, whose constituents are non-degenerate ultra-cold ions, relativistically degenerate electrons, and positrons. By using the reductive perturbation technique, Korteweg–deVries Burger and modified Korteweg–deVries Burger equations are derived. It is shown that only compressive shock waves can propagate in such a plasma system. The effects of geometry, the ion kinematic viscosity, and the positron concentration are examined on the ion acoustic shock potential and electric field profiles. It is found that the properties of ion acoustic shock waves in a non-planar geometry significantly differ from those in planar geometry. The present study has relevance to the dense plasmas, produced in laboratory (e.g., super-intense laser-dense matter experiments) and in dense astrophysical objects.

Modified Ion-Acoustic Shock Waves and Double Layers in a Degenerate Electron-Positron-Ion Plasma in Presence of Heavy Negative Ions

“…Eliasson and Shukla [33] examined a super-dense quantum plasma consisting of relativistically degenerate electrons and fully ionized ions, and figured out the formation of electrostatic shock structures. Rahman et al [34] also investigated an e-p-i plasma and studied the salient features of compressive shock waves. Mamun and Shukla [28] analyzed a quantum plasma with non-relativistic and ultra-relativistic degenerate electron fluids and strongly coupled degenerate ion fluids and rigorously investigated the salient features of shock waves.…”

“…More recently, a large number of authors [27,[38][39][40][41][42][43] studied the basic properties of solitary, and shock waves by deriving the Korteweg-de Vries (K-dV), modified K-dV (comes from higher order of K-dV equation), Gardner (comes from higher term of modified K-dV equation), and Burgers equation for planar and nonplanar cases in considering different types of effects [34,35,44,45]. But the interesting point is to note that the Burgers equation for nonplanar case is called modified Burgers equation [46][47][48].…”

Nonplanar Positron-Acoustic Shock Waves in Astrophysical Plasmas

“…Recently, a great attention has been attracted in comprehending the principal properties of matter under extreme conditions [11][12][13][14], that are found in several astrophysical compact objects. The astrophysical compact objects support themselves by degenerate electron-positron pressure.…”

Relativistic degenerate effects of electrons and positrons on modulational instability of quantum ion acoustic waves in dense plasmas with two polarity ions

“…[41] The nonlinear solitary waves and shock waves were studied in relativistically degenerate electrons and positrons plasmas. [42][43][44][45] Accordingly in the present paper, we study the QIAWs in unmagnetized plasmas consisting of positive and negative ions as well as inertialess relativistically degenerate electrons and positrons. Here the ions are considered to be classical and inertial, while the electrons and positrons are treated as being inertialess, which will be considered as weakly relativistically degenerate plasma or an ultrarelativistic one.…”