A Clifford inequality for semistable curves

Abstract Let X be a semistable curve and L line bundle whose multidegree is uniform, i.e., in the range between those of structure sheaf dualizing . We establish an upper bound for $$h^0(X,L)$$ h 0 ( X , L ) , which generalizes classic Clifford inequality smooth curves. The depends on total degree connectivity properties dual graph It sharp, sense that any there exist bundles with uniform achieve bound.