Abstract
We prove the weak-strong uniqueness for measure-valued solutions of the incompressible Euler equations. These were introduced by R. DiPerna and A. Majda in their landmark paper [10], where in particular global existence to any L2 initial data was proven. Whether measure-valued solutions agree with classical solutions if the latter exist has apparently remained open. We also show that DiPerna's measure-valued solutions to systems of conservation laws have the weak-strong uniqueness property.