Nonlinear Electroacoustic Waves in Fully Relativistic Astrophysical Degenerate Plasmas

The solitary structures associated with the electroacoustic (EA) waves, in which the cold degenerate electron and positron fluids provide the inertia, the hot electrons and positrons following the Maxwellian distribution give rise to the restoring force, and stationary heavy ions maintain the background charge neutrality condition, have been theoretically studied. The fully relativistic hydrodynamic model is utilized to derive the Korteweg-de Vries equation. The stationary solitary wave solution is obtained and numerically analyzed to identify the basic features of the solitary structures that are found to be formed in the astrophysical relativistic degenerate dense plasmas. It is found that the combined effects of electron and positron dynamics, stationary heavy ions, and relativistic degeneracy play a very significant role in modifying the basic properties of the EA waves in such degenerate dense plasmas. The latter usually occurs in the compact astrophysical objects, such as white dwarfs, neutron stars, and so on.