The Beale-Kato-Majda criterion is a continuation criterion for smooth solutions of the three-dimensional Euler's equations
of inviscid motion. Let be such a solution, let
be its vorticity, and let
be its maximal time of smooth existence. The solution can
be continued past a time
provided
Equivalently, finite-time blow-up at
requires this integral to diverge as
approaches
. Here the
norm is the essential
supremum over space (Beale et al. 1984).