摘要:
There is a long-standing attempt to extend the theory of linear dieren- tial systems that are additively perturbed by higher-order terms to dierential systems whose lowest degree terms are homogeneous forms of degree m with additive perturbations of degree greater than m. In order to do this, the rst step must be the construction of a complete theory of dierential systems whose rate functions are homogeneous of degree m (and no higher order perturbations). This will depend upon a full understanding of m-ary algebras over real or com- plex eld, algebras which are commutative, but in general non-associative. The purpose of this work is to give some contributions to this problem. We will gen- eralize results of C. Coleman [C1] and L. Markus [Ma]. Namely, the two results together say: Theorem. Let A = R be an m-ary real algebra. If m = 2 or n is odd, then n A has at least one nilpotent or idempotent element. Moreover, the corresponding dierential system has at least one line of critical points or a pair of opposite integral rays.