Sufficient conditions for infinite-horizon . . .

After a brief survey of the literature about sufficient conditions, we give dierent sucient conditions of optimality for infinite-horizon calculus of variations problems in the general (non concave) case. Some sucient conditions are obtained by extending to the infinite-horizon setting the techniques of extremal elds. Others are obtained in a special case of reduction to nite horizon. The last result uses auxiliary functions. We treat ve notions of optimality. Our problems are essentially motivate