A footnote to a paper by Noma
Let be a globally generated ample vector bundle of rank on a complex projective smooth surface . By extending a recent result by A. Noma, we classify pairs as above satisfying .
Let be a globally generated ample vector bundle of rank on a complex projective smooth surface . By extending a recent result by A. Noma, we classify pairs as above satisfying .
In this note, we prove that the -fundamental group scheme is a birational invariant for smooth projective varieties. We prove that the -fundamental group scheme is naturally a quotient of the Nori fundamental group scheme. For elliptic curves, it turns out that the -fundamental group scheme and the Nori fundamental group scheme coincide. We also consider an extension of the Nori fundamental group scheme in positive characteristic using semi-essentially finite vector bundles, and prove that in...
Let be a complex algebraic group, simple and simply connected, a maximal torus and the Weyl group. One shows that the coarse moduli space parametrizing -equivalence classes of semistable -bundles over an elliptic curve is isomorphic to . By a result of Looijenga, this shows that is a weighted projective space.
In this paper we show that on a general hypersurface of degree r = 3,4,5,6 in P5 a rank 2 vector bundle ε splits if and only if h1ε(n) = h2ε(n) = 0 for all n ∈ Z. Similar results for r = 1,2 were obtained in [15], [16] and [2].