网站首页  英汉词典

请输入您要查询的英文单词:

 

单词 Atoroidal
释义

Atoroidal

英语百科

Atoroidal

In mathematics, an atoroidal 3-manifold is one that does not contain an essential torus. There are two major variations in this terminology: a torus may be defined geometrically, as an embedded, non-boundary parallel, incompressible torus, or it may be defined algebraically, as a subgroup \mathbb Z\times\mathbb Z of its fundamental group that is not conjugate to a peripheral subgroup (i.e. the image of the map on fundamental group induced by an inclusion of a boundary component). The terminology is not standardized, and different authors require atoroidal 3-manifolds to satisfy certain additional restrictions. For instance:

随便看

 

英汉网英语在线翻译词典收录了3779314条英语词汇在线翻译词条,基本涵盖了全部常用英语词汇的中英文双语翻译及用法,是英语学习的有利工具。

 

Copyright © 2004-2024 encnc.com All Rights Reserved
更新时间:2025/6/17 14:13:20