### Existence and uniqueness of solutions to dynamical unilateral contact problems with coulomb friction: the case of a collection of points

This study deals with the existence and uniqueness of solutions to dynamical problems of finite freedom involving unilateral contact and Coulomb friction. In the frictionless case, it has been established [P. Ballard, 154 (2000) 199–274] that the existence and uniqueness of a solution to the Cauchy problem can be proved under the assumption that the data are analytic, but not if they are assumed to be only of class . Some years ago, this finding was extended [P. Ballard and S. Basseville,...