University of Isfahan International Journal of Group Theory 2251-7650 2 1 2013 03 01 Omissible extensions of SL2(k) where k is a field of positive characteristic 145 155 2739 10.22108/ijgt.2013.2739 EN Martyn Dixon The University of Alabama Martin Evans The University of Alabama Howard Smith Bucknell University Journal Article 2012 12 19 A normal subgroup $N$ of a group $G$ is said to be an‎ <em>omissible</em> subgroup of $G$ if it has the following property‎: ‎whenever $X\leq G$ is such that $G=XN$‎, ‎then $G=X$‎. ‎In this note we construct various groups $G$‎, ‎each of which has an omissible subgroup $N\neq 1$ such that $G/N\cong SL_2(k)$ where $k$ is a field of positive characteristic‎. https://ijgt.ui.ac.ir/article_2739_5cbd1f85252078e642252fe7f93e9285.pdf