University of Isfahan International Journal of Group Theory 2251-7650 6 1 2017 03 01 Torsion units for some projected special linear groups 37 53 12010 10.22108/ijgt.2017.12010 EN Joe Gildea Senior Lecturer in Mathematics, Department of Mathematics Journal Article 2015 11 25 In this paper, we investigate the Zassenhaus conjecture for $PSL(4,3)$ and $PSL(5,2)$. Consequently,<br /> we prove that the Prime graph question is true for both groups. Zassenhaus Conjecture torsion unit partial augmentation integral group ring https://ijgt.ui.ac.ir/article_12010_d29092385cbddb565eeadc78f175a1e0.pdf