A remark on subbundles of symplectic and orthogonal vector bundles over curves
arXiv:math/0407323
Abstract
We review the notions of symplectic and orthogonal vector bundles over curves, and the connection between principal parts and extensions of vector bundles. We give a criterion for a certain extension of rank 2n to be symplectic or orthogonal. We then describe almost all of its rank n vector subbundles using graphs of sheaf homomorphisms, and give criteria for the isotropy of these subbundles.
13 pages; refinement of main result added