Maximal Cohen--Macaulay modules over hypersurface rings.
A well known result of Miyaoka asserts that a complex projective manifold is uniruled if its cotangent bundle restricted to a general complete intersection curve is not nef. Using the Harder-Narasimhan filtration of the tangent bundle, it can moreover be shown that the choice of such a curve gives rise to a rationally connected foliation of the manifold. In this note we show that, conversely, a movable curve can be found so that the maximal rationally connected fibration of the manifold may be recovered...
We study general elements of moduli spaces of rank-2 stable holomorphic vector bundles on and their minimal free resolutions. Incidentally, a quite easy proof of the irreducibility of is shown.
Sia un fibrato in coniche standard con curva discriminante di grado . La varietà delle sezioni minime delle superfici , dove è una curva di grado , si spezza in due componenti e . Si prova che, mediante la mappa di Abel-Jacobi , una di queste componenti domina la Jacobiana intermedia , mentre l'altra domina il divisore theta . Questi risultati vengono applicati ad alcuni threefold di Fano birazionalmente equivalenti a un fibrato in coniche. In particolare si prova che il generico...
We present an example which confirms the assertion of the title.