EntityQ2997419· pop 10· linked from 201 articlesprojective linear groupSign in to saveconstruction in group theoryConnectionsgroup actionEntitycross-ratioEntityorthogonal groupEntityhomographyEntityblock designEntityclassical groupEntityfieldEntityroot of unityEntityrepresentation theoryEntitycenterEntityMöbius transformationEntityhomotopy groupEntitySL2(R)Entityicosahedral symmetryEntityperfect groupEntitycollineationEntityADE classificationEntitymathematicsEntityphysicsEntityalgebraEntityCategoriesLie groupsProjective geometry