On Stable Bundles of Ranks 2 and 3 on P^3

Abstract

We study rank 3 stable bundles E on P^3 as extensions of a line bundle B on a smooth surface S in P^3 by the direct sum of three copies of O_{P^3}(-ν). In most cases, S (the dependency locus of three sections of E(ν)) lies in the Noether-Lefschetz locus. We give a detailed analysis when S contains a line L and B is constructed from divisors of the form aL+bC for H=L+C a hyperplane section of S. We study the parameter space of this construction and compare it to the full (Gieseker-Maruyama) moduli space. We also analyse the case when B is a power of the hyperplane bundle. The same approach is used to study rank 2 bundles on P^3.