A theoretical investigation on the propagation of positron-acoustic shock waves （PASWs） in an unmagnetized, collisionless, dense plasma （containing non-relativistic inertial cold positrons, non-relativistic or ultr...A theoretical investigation on the propagation of positron-acoustic shock waves （PASWs） in an unmagnetized, collisionless, dense plasma （containing non-relativistic inertial cold positrons, non-relativistic or ultra-relativistic degenerate electron and hot positron fluids and nondegenerate positively charged immobile ions） is carried out by employing the reductive perturbation method. The Burgers equation and its stationary shock wave solution are derived and numerically analyzed. It is observed that the relativistic effect （i.e., the presence of non/ultra- relativistic electrons and positrons） and the plasma particle number densities play vital roles in the propagation of PASWs. The implications of our results in space and interstellar compact objects including non-rotating white dwarfs, neutron stars, etc. are briefly discussed.展开更多
This paper studies the Riemann problem for a system of nonlinear degenerate wave equations in elasticity. Since the stress function is neither convex nor concave, the shock condition is degenerate. By introducing a de...This paper studies the Riemann problem for a system of nonlinear degenerate wave equations in elasticity. Since the stress function is neither convex nor concave, the shock condition is degenerate. By introducing a degenerate shock under the generalized shock condition, the global solutions are constructively obtained case by case.展开更多
文摘A theoretical investigation on the propagation of positron-acoustic shock waves （PASWs） in an unmagnetized, collisionless, dense plasma （containing non-relativistic inertial cold positrons, non-relativistic or ultra-relativistic degenerate electron and hot positron fluids and nondegenerate positively charged immobile ions） is carried out by employing the reductive perturbation method. The Burgers equation and its stationary shock wave solution are derived and numerically analyzed. It is observed that the relativistic effect （i.e., the presence of non/ultra- relativistic electrons and positrons） and the plasma particle number densities play vital roles in the propagation of PASWs. The implications of our results in space and interstellar compact objects including non-rotating white dwarfs, neutron stars, etc. are briefly discussed.
基金Project supported by the National Natural Science Foundation of China(No.10971130)the Shanghai Leading Academic Dissipline Project(No.J50101)
文摘This paper studies the Riemann problem for a system of nonlinear degenerate wave equations in elasticity. Since the stress function is neither convex nor concave, the shock condition is degenerate. By introducing a degenerate shock under the generalized shock condition, the global solutions are constructively obtained case by case.
