Scalar field critical collapse in 2 + 1 dimensions

We carry out numerical experiments in the critical collapse of a spherically symmetric massless scalar field in 2+1 spacetime dimensions in the presence of a negative cosmological constant and compare them against a new theoretical model. We approximate the true critical solution as the n = 4 Garfinkle solution, matched at the light cone to a Vaidya-like solution, and corrected to leading order for the effect of [Lambda]