ON MASS CONCENTRATION FOR THE CRITICAL GENERALIZED KORTEWEG-DE VRIES EQUATION

We show that blow-up solutions of the critical generalized Korteweg-de Vries equation in H-1(R) concentrate at least the mass of the ground state at the blow-up time. The I-method is used to prove a slightly weaker result in H-s(R) with 16/17 < s < 1. Under an assumption on the precise blow-up rate, we are able to use similar arguments to prove a more precise analogue of the H-1(R) concentration result over the same range of s.