Dipartimento di Matematica, Universita di Trento, 38050 Povo (TN), Italia, e-mail: ballico@science.unitn.it, fax: Italy+0461+881624Dipartimento di Matematica, Politecnico di Torino, 10129 Torino, Italia, e-mail: chiarli@polito.it, sgreco@polito.it
Abstract: We study non-degenerate subschemes $Y \subseteq P^n$ with degenerate general hyperplane section. Our results consist in some steps towards a classification of such schemes $Y$, in arbitrary characteristic when $Y$ is a locally Cohen-Macaulay curve (with more details for $n=4,5$) and in characteristic zero when $Y$ is an $S_2$ equidimensional scheme of dimension $\geq 2$. Our main results are proved for connected schemes.
Classification (MSC91): 14H50; 14M99
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