Coherent systems and Butler's conjecture
Leticia BRAMBILA-PAZ
(CIMAT, Guanajuato, Mexico)

Let (E, V) be a general generated coherent system of type (n, d, n+m) on a general non-singular irreducible complex projective curve. A conjecture of D. C. Butler relates the semistability of E to the semistability of the kernel of the evaluation map V x O_X -> E. In this talk, some results will be given about the existence of generated coherent systems and a necessary condition is given for the Butler conjecture to be satisfied.