Grbner bases in difference-differential modules with coefficients in a commutative ring

• 作 者: ZHOU Meng HUANG GuanLi
• 机 构: SchoolofMathematicsandSystemScience,SchoolofAutomationEngineering
• 出 处: 中国科学：数学英文版
• 发表日期: 2012年9期
• 关键词: 模块 差分 一年级 WINKLER 环系 微分算子 交换环 Grobner basis difference-differential module gen
• 基金项目: Acknowledgements This work was supported by National Natural Science Foundation of China （Grant No 10871017） and Natural Science Foundation of Beijing （Grant No. 1102026）.

Let x be an m-dimensional umbilic-free hypersurface in an (m + 1)-dimensional unit sphere Sm+1 (m≥3). In this paper, we classify and explicitly express the hypersurfaces with two distinct principal curvatures and closed Mbius form, and then we characteri