University of IsfahanInternational Journal of Group Theory2251-76502120130301On some invariants of finite groups109115264210.22108/ijgt.2013.2642ENJan KrempaInstitute of Mathematics, University of WarsawAgnieszka StockaInstitute of Mathematics
University of BiałystokJournal Article20121218A 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 $Xleq G$ is such that $G=XN$, then $G=X$. In this note we construct various groups $G$, each of which has an omissible subgroup $Nneq 1$ such that $G/Ncong SL_2(k)$ where $k$ is a field of positive characteristic.http://ijgt.ui.ac.ir/article_2642_9f742c032856a8f0dcd5a8b7de56b25b.pdf