Concentration Phenomenon of Riemann Solutions for the Relativistic Euler Equations with the Extended Chaplygin Gas

The solutions of the Riemann problem for the isentropic relativistic Euler equations with the extended Chaplygin gas are constructed completely for all the possible cases. The asymptotic limits of solutions to the Riemann problem for the relativistic Euler equations are captured in detail when the equation of state of extended Chaplygin gas becomes the one of Chaplygin gas. It is shown that the formations of delta shock wave solution and two-contact-discontinuity solution are derived and analyzed rigorously during the limiting process.