ENERGY CONSERVATION FOR 2D EULER WITH VORTICITY IN L(log L)α

In these notes we discuss the conservation of the energy for weak solutions of the two- dimensional incompressible Euler equations. Weak solutions with vorticity in L∞ t Lp x with p ≥ 3/2 are always conservative, while for less integrable vorticity the conservation of the energy may depend on the approximation method used to construct the solution. Here we prove that the canonical approximations introduced by DiPerna and Majda provide conservative solutions when the initial vorticity is in the class L(log L)α with α > 1/2