Invited talk, South China Normal University, Sept. 8, 2015.
http://202.116.32.252:8080/maths/index.php?m=content&c=index&a=show&catid=29&id=4777
In this talk, I will show a priori estimates for the three-dimensional compressible Euler equations with moving physical vacuum boundary, the $\gamma$-gas law equation of state for $\gamma=2$ and the general initial density $\rho_0 \in H^5$. I derive a mixed space-time interpolation inequality which play a vital role in the energy estimates and obtain some extra estimates for the space-time derivatives of the velocity in $L^3$, which is different from the known results.