一类引人注目的左序群：Hecke群的中心扩张

分圆Hecke代数的泛Specht模

Universal Specht modules for cyclotomic Hecke algebras

分圆Hecke代数的分次Specht模$S^λ$带有一个特殊的生成向量$z^λ\in S^λ$，它可以被认为是“权的最高权向量$λ$“.本文描述了作为由$z^λ$生成的分次模的Specht模块$S^λ$的{ \em定义关系}。前三个关系精确地说明了$z^λ$是权重$λ$的最高权向量意味着什么。其余的关系是经典{ \em Garnir关系}的齐次类似物。齐次Garnir关系比经典关系简单{ \em}，它与一类特殊的满足辫子关系的齐次算子族相联系.

Ordered groups and topology

This is a draft of a book submitted for publication by the AMS. Its theme is the remarkable interplay, accelerating in the last few decades, between topology and the theory of orderable groups, with applications in both directions. It begins with an introduction to orderable groups and their algebraic properties. Many of the algebraic results are proved by topological methods, via consideration of the space of orderings. After a discussion Hölder's theorem and some dynamical aspects of orderable groups, we provide explicit orderings of important groups in topology: free groups and most surface…