“…It is well known that, for general initial data u0∈L2, weak solutions are not unique, see [14] and references therein. Moreover, uniqueness has not been established even under additional restrictions on integrability of vorticity, with the exception of ω0=curl u0∈L∞, see [15], and slightly weaker spaces close to L∞, see [16], and there is some indication of non-uniqueness of weak solutions if, for any 1≤p<normal∞, ω0∈Lp, see [17]. It is natural, therefore, to focus on special weak solutions, such as those obtained as limits of solutions of the more physically realistic Navier–Stokes equations.…”