|
In mathematics, the Herzog–Schönheim conjecture is a combinatorial problem in the area of group theory, posed by Marcel Herzog and Jochanan Schönheim in 1974.〔. As cited by .〕 Let be a group, and let : be a finite system of left cosets of subgroups of . Herzog and Schönheim conjectured that if forms a partition of with , then the (finite) indices cannot be distinct. In contrast, if repeated indices are allowed, then partitioning a group into cosets is easy: if is any subgroup of with index then can be partitioned into left cosets of . ==Subnormal subgroups== In 2004 Zhi-Wei Sun proved an extended version of the Herzog–Schönheim conjecture in the case where are subnormal in .〔.〕 A basic lemma in Sun's proof states that if are subnormal and of finite index in , then : and hence : where denotes the set of prime divisors of . 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「Herzog–Schönheim conjecture」の詳細全文を読む スポンサード リンク
|