Families of special Weierstrass points

Abstract

The purpose of this Note is to show that loci of (special) Weierstrass points on the fibers of a family π : X → S of smooth curves of genus g ⩾ 2 can be studied by simply pulling back the Schubert calculus naturally living on a suitable Grassmann bundle over X . Using such an idea we prove new results regarding the decomposition in A ∗ ( X ) of the class of the locus of Weierstrass points having weight at least 3 as the sum of classes of Weierstrass points having “bounded from below” gaps sequences. To cite this article: L. Gatto, P. Salehyan, C. R. Acad. Sci. Paris, Ser. I 347 (2009).