Multiple quantum products in toric varieties

We generalize the author's formula for Gromov-Witten invariants of symplectic toric manifolds (see math.AG/0006156) to those needed to compute the quantum product of more than two classes directly, i.e. involving the pull-back of the Poincar\'e dual of the point class in the Deligne-Mumford spaces $\mathcal{M}_{0,m}$.Comment: 10 pages, LaTeX with amsart style; v2: example section extended to cover a bigger class of toric bundles; v3: proof of Lemma 10 improved, minor change

C*-algebras for categories of paths asociated to the Baumslag-Solitar groups

In this paper we describe the C*-algebras associated to the Baumslag-Solitar groups with the ordering defined by the usual presentations. These are Morita equivalent to the crossed product C*-algebras obtained by letting the group act on its directed boundary. We use the method of categories of paths to define the algebras, and to deduce the presentation by generators and relations. We obtain a complete description of the Toeplitz algebras, and we compute the K-theory of the Cuntz-Kreiger algebras.Comment: To appear in the Journal of the London Mathematical Societ