TY - JOUR T1 - On 2-step, corank 2 nilpotent sub-Riemannian metrics JF - SIAM J. Control Optim., 50 (2012) 559–582 Y1 - 2012 A1 - Davide Barilari A1 - Ugo Boscain A1 - Jean-Paul Gauthier AB - In this paper we study the nilpotent 2-step, corank 2 sub-Riemannian metrics\\r\\nthat are nilpotent approximations of general sub-Riemannian metrics. We exhibit optimal syntheses for these problems. It turns out that in general the cut time is not equal to the first conjugate time but has a simple explicit expression. As a byproduct of this study we get some smoothness properties of the spherical Hausdorff measure in the case of a generic 6 dimensional, 2-step corank 2 sub-Riemannian metric. PB - Society for Industrial and Applied Mathematics UR - http://hdl.handle.net/1963/6065 U1 - 5950 U2 - Mathematics U3 - Functional Analysis and Applications U4 - -1 ER -