Abstract
It is well known that a nondegenerate projective subvariety \({X \subset \mathbb {P}^r}\) of degree d and codimension c > 1 has minimal degree (i.e., d = c + 1) if and only if index(X) ≥ c if and only if X has no multisecant c-space. In this paper we extend this result by classifying varieties with index(X) ≥ c − s or with no multisecant (c − s)-space for s = 1 and 2.
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The first and third named authors were supported by the National Researcher program 2010-0020413 of NRF and MEST. The second named author was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (No. 20090073305).
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Lee, W., Park, E. & Woo, Y. On multisecants and the Green-Lazarsfeld index of projective varieties. Arch. Math. 96, 525–530 (2011). https://doi.org/10.1007/s00013-011-0270-1
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DOI: https://doi.org/10.1007/s00013-011-0270-1