翻訳と辞書 |
Smooth completion : ウィキペディア英語版 | Smooth completion In algebraic geometry, the smooth completion (or smooth compactification) of a smooth affine algebraic curve ''X'' is a complete smooth algebraic curve which contains ''X'' as an open subset.〔Griffiths, 1972, p. 286.〕 Smooth completions exist and are unique over a perfect field. ==Examples== An affine form of a hyperelliptic curve may be presented as where and () has distinct roots and has degree at least 5. The Zariski closure of the affine curve in is singular at the unique infinite point added. Nonetheless, the affine curve can be embedded in a unique compact Riemann surface called its smooth completion. The projection of the Riemann surface to is 2-to-1 over the singular point at infinity if has even degree, and 1-to-1 (but ramified) otherwise. This smooth completion can also be obtained as follows. Project the affine curve to the affine line using the x-coordinate. Embed the affine line into the projective line, then take the normalization of the projective line in the function field of the affine curve.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Smooth completion」の詳細全文を読む
スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|