Moduli spaces of framed sheaves on certain ruled surfaces over elliptic curves

Research paper by Thomas A. Nevins

Indexed on: 25 Aug '00Published on: 25 Aug '00Published in: Mathematics - Algebraic Geometry


Fix a ruled surface S obtained as the projective completion of a line bundle L on a complex elliptic curve; we study the moduli problem of parametrizing certain pairs consisting of a sheaf E on S and a map of E to a fixed reference sheaf on S. We prove that the full moduli stack for this problem is representable by a scheme in some cases. Moreover, the moduli stack admits an action by the group ${\mathbf C}^*$, and we determine its fixed-point set, which leads in some special cases to explicit formulas for the rational homology of the moduli space.