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arXiv · 1302.0824

Unobstructedness of filling secants and the Gruson-Peskine general projection theorem

Ziv Ran
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Abstract

We prove an unobstructedness result for deformations of subvarieties constrained by intersections with another, fixed subvariety. We deduce smoothness and expected-dimension results for multiple-point loci of generic projections, mainly from a point or a line, or for fibres of embedding dimension 2 or less. The current version is a substantial enhancement of the previous one, including for the first time results on projection from a line.

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Ziv Ran. 2013-02-04. Unobstructedness of filling secants and the Gruson-Peskine general projection theorem. https://doi.org/10.1215/00127094-2881483

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