Coherent systems on curves of compact type

[摘要] Let C be a polarized nodal curve of compact type. In this paper we study coherent systems (E, V) on C given by a depth one sheaf E having rank r on each irreducible component of C and a subspace V subset of H-0(E) of dimension k. Moduli spaces of stable coherent systems have been introduced by King and Newstead (1995) and depend on a real parameter a. We show that when k >= r, these moduli spaces coincide for alpha big enough. Then we deal with the case k = r + 1: when the degrees of the restrictions of E are big enough we are able to describe an irreducible component of this moduli space by using the dual span construction. (C) 2020 Elsevier B.V. All rights reserved.

[发布日期] 2020-12-01

[关键词] Coherent system;Stability;Curves of compact type;Nodal curves