抄録
It is known that if a projective variety X in P N is reflexive with respect to the projective dual, then the Gauss map of X defined by embedded tangent spaces is separable, and moreover that the converse is not true in general. We prove that the converse holds under the assumption that X is of dimension two. Explaining the subtleness of the problem, we present an example of smooth projective surfaces in arbitrary positive characteristic, which gives a negative answer to a question raised by S. Kleiman and R. Piene on the inseparability of the Gauss map.
本文言語 | English |
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ページ(範囲) | 699-703 |
ページ数 | 5 |
ジャーナル | Mathematische Zeitschrift |
巻 | 256 |
号 | 4 |
DOI | |
出版ステータス | Published - 2007 8月 |
ASJC Scopus subject areas
- 数学 (全般)