Some results on deformations of sections of vector bundles

الأصل · EN

Let E be a vector bundle on a smooth complex projective variety X. We study the family of sections sₜ∈ H⁰(E⊗ Lₜ) where Lₜ∈ Pic⁰(X) is a family of topologically trivial line bundle and L₀=Oₓ, that is, we study deformations of s=s₀. By applying the approximation theorem of Artin [2] we give a transversality condition that generalizes the semi-regularity of an effective Cartier divisor. Moreover, we obtain another proof of the Severi-Kodaira-Spencer theorem [4]. We apply our results to give a lower bound to the continuous rank of a vector bundle as defined by Miguel Barja [3] and a proof of a piece of the generic vanishing theorems [6] and [7] for the canonical bundle. We extend also to higher dimension a result given in [8] on the base locus of the paracanonical base locus for surfaces.