Formation of δ-shock waves in isentropic fluids.

This paper studies a Riemann problem for the isentropic Euler equations and addresses two gaps in the literature concerning positive pressures. Such study is made using a product of distributions and a solution concept that extends the classical solution concept. Under certain conditions, even for positive pressures, it is shown that the Riemann problem has solutions, which are δ -shock waves. As particular cases, this work examines polytropic gases, pressureless gases, and Chaplygin gases. [ABSTRACT FROM AUTHOR]