%0 Journal Article %T 可以表示成3个或4个交换子群并的群<br>On Groups Which Are the Unions of Three or Four Abelian Subgroups %A 郭红如 %A 吕恒< %A br> %A GUO Hong-ru %A LV Heng %J 西南大学学报(自然科学版) %D 2017 %R 10.13718/j.cnki.xdzk.2017.08.014 %X 主要证明了一个群如果可以表示为3个或4个交换子群的并,则下列结论成立:① 群<i>G</i>可以表示成3个交换子群的并当且仅当<i>G</i>/<i>Z</i>(<i>G</i>)?<i>Z</i><sub>2</sub>×<i>Z</i><sub>2</sub>;② 群<i>G</i>可以表示成4个交换子群的并当且仅当<i>G</i>/<i>Z</i>(<i>G</i>)?<i>S</i><sub>3</sub>或<i>G</i>/<i>Z</i>(<i>G</i>)?<i>Z</i><sub>3</sub>×<i>Z</i><sub>3</sub>.<br>This paper investigates the groups which are the unions of three or four abelian subgroups and obtains the following results: (1) Group <i>G</i> is the union of three abelian subgroups if and only if <i>G</i>/<i>Z</i>(<i>G</i>)?<i>Z</i><sub>2</sub>×<i>Z</i><sub>2</sub>; (2) Group <i>G</i> is the union of four abelian subgroups if and only if <i>G</i>/<i>Z</i>(<i>G</i>)?<i>S</i><sub>3</sub> or <i>G</i>/<i>Z</i>(<i>G</i>)?<i>Z</i><sub>3</sub>×<i>Z</i><sub>3</sub> %K 交换子群 %K 非交换集 %K 幂零群< %K br> %K abelian subgroup %K non-commuting set %K nilpotent group %U http://xbgjxt.swu.edu.cn/jsuns/html/jsuns/2017/8/201708014.htm