No abstract

We extend to the analytic D-module case our results in the algebraic case (see [3]), namely, we associate with any monogeneous module over the ring D of germs of linear differential operators at the origin of C n , with holomorphic coefficients, a combinatorial object which we call the standard fan of this D-module (see chapter 6 for a precise geometric description of this object). The main tool of the proof is the homogenization techniques and a convergent division theorem that we prove in the homogenization ring D[t].

Contents 10 2. Irreducible numerical semigroups 11 2.1. Decomposition of a numerical semigroup into irreducible semigroups 15 2.2. Free numerical semigroups 15 3. Semigroup of an irreducible meromorphic curve 17 3.1. Newton-Puiseux theorem 17 3.2. The local case 27 3.3. The case of curves with one place at infinity 28 4. Minimal presentations 32 5. Factorizations 38 5.1. Length based invariants 38 5.2. Distance based invariants 41 5.3. How far is an irreducible from being prime 43 References 45

No abstract

Abstract. Delorme suggested that the set of all complete intersection numerical semigroups can be computed recursively. We have implemented this algorithm, and particularized it to several subfamilies of this class of numerical semigroups: free and telescopic numerical semigroups, and numerical semigroups associated to an irreducible plane curve singularity. The recursive nature of this procedure allows us to give bounds for the embedding dimension and for the minimal generators of a semigroup in any of these families.