"Crack kinking and energy estimates at the tip of a 2D
fracture"

Abstract. We discuss a stability criterion for 2D linearized elasticity, at
the tip of a straight crack, and its consequences. Our approach suffers two
drawbacks, as up to now, we cannot take into account the
non-interpenetration condition along the fracture, and rely on energy
estimates at the tip which are known only for very smooth fractures. In
the 2D antiplane (scalar) setting, we also show how to weaken these
regularity assumptions. (joint with G. Francfort, J.-J. Marigo and A. Lemenant).