On 4-generated bundles and directly linked subcanonical curves

Given a subcanonical curve r in P3, we study conditions under which r is directly linked to another subcanonical curve r’. We show that this happens when the rank 2 bundle E associated to r admits a surjection U: @“O+( -a,) + E, a, E Z. We give an explicit construction of such a r starting with surjection u and we prove that the numbers ai appearing in ZA are uniquely determined by E: this implies that we have at most 3 possibilities for the numerical characters of a subcanonical curve directly linked to K