Gianluca Occhetta

activity

20002005

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math.AG2005

Fano manifolds with long extremal rays

Marco Andreatta, Gianluca Occhetta

Let X be a Fano manifold of pseudoindex i_X whose Picard number is at least two and let R be an extremal ray of X with exceptional locus Exc(R). We prove an inequality which bounds…

math.AG2003

Generalized Mukai conjecture for special Fano varieties

Marco Andreatta, Elena Chierici, Gianluca Occhetta

Let X be a Fano variety of dimension n, pseudoindex i_X and Picard number ρ_X. A generalization of a conjecture of Mukai says that ρ_X(i_X-1)\le n. We prove that the conjecture hol…

math.AG2000

Special rays in the Mori cone of a projective variety

Marco Andreatta, Gianluca Occhetta

Let $X$ be a smooth $n$ -dimensional projective variety over an algebraically closed field $k$ such that $K_{X}$ is not nef. We give a characterization of non nef extremal rays of $X$ …