Gq. Chen et Pg. Lefloch, ENTROPIES AND WEAK SOLUTIONS OF THE COMPRESSIBLE ISENTROPIC EULER EQUATIONS, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 324(10), 1997, pp. 1105-1110
In this Note, we study the system of isentropic Euler equations for co
mpressible fluids, with a general equation of state. We establish the
existence of the fundamental kernel that generates the family of weak
entropies, and study its singularities. The kernel is the solution of
an equation of Euler-Poisson-Darboux type, and its partial derivative
with respect to the density variable tends to a Dirac measure as the d
ensity approaches zero. We prove a new reduction theorem for the Young
measures associated with the compressible Euler system. From these re
sults, we deduce the existence, compactness, and asymptotic decay of m
easurable and bounded entropy solutions.