%0 Journal Article %T 用不可补子群个数刻画单群<i>A</i><sub>5</sub><br>Characterizing the Simple Group <i>A</i><sub>5</sub> by the Number of Uncomplemented Subgroups %A 黄宇 %A 宋科研< %A br> %A HUANG Yu %A SONG Ke-yan %J 西南大学学报(自然科学版) %D 2018 %R 10.13718/j.cnki.xdzk.2018.12.014 %X 设<i>G</i>是有限群,<i>H</i>≤<i>G</i>.如果<i>G</i>中存在子群<i>K</i>≤<i>G</i>,满足<i>G</i>=<i>KH</i>,且<i>H</i>∩<i>K</i>=1,那么称<i>H</i>在<i>G</i>中可补.研究子群的可补性对有限群结构和性质的影响是群论研究中十分重要的课题.给出了5次交错群<i>A</i><sub>5</sub>的一个新刻画,即60阶群<i>G</i>?<i>A</i><sub>5</sub>的充分必要条件是<i>G</i>中只有46个不可补子群.<br>Let <i>G</i> be a finite group, <i>H</i>≤<i>G</i>. If there exists a subgroup <i>K</i> of <i>G</i> such that <i>G</i>=<i>HK</i> and <i>H</i>∩<i>K</i>=1, then <i>H</i> is called complemented in <i>G</i>. The subgroup's complementarity on the structure and properties of finite groups is a very important topic in group theory. A new characterization of the alternating group <i>A</i><sub>5</sub> is given, i.e., let G be a group of order 60, <i>G</i>?<i>A</i><sub>5</sub> if and only if G only has 46 uncomplemented subgroups %K 不可补子群 %K 5次交错群 %K Sylow子群< %K br> %K uncomplemented subgroup %K alternating group of degree 5 %K Sylow subgroup %U http://xbgjxt.swu.edu.cn/jsuns/html/jsuns/2018/12/20181214.htm