@article { author = {Pourmirzaei, A. and Hassanzadeh, M. and Mashayekhy, B.}, title = {ON RELATIVE CENTRAL EXTENSIONS AND COVERING PAIRS}, journal = {Journal of Algebraic Systems}, volume = {4}, number = {1}, pages = {1-13}, year = {2016}, publisher = {Shahrood University of Technology}, issn = {2345-5128}, eissn = {2345-511X}, doi = {10.22044/jas.2016.724}, abstract = {Let (G;N) be a pair of groups. In this article, first we con-struct a relative central extension for the pair (G;N) such that specialtypes of covering pair of (G;N) are homomorphic image of it. Second, weshow that every perfect pair admits at least one covering pair. Finally,among extending some properties of perfect groups to perfect pairs, wecharacterize covering pairs of a perfect pair (G;N) under some extraassumptions.}, keywords = {Pair of groups,Covering pair,Relative central extension,Isoclinism of pairs of groups}, url = {https://jas.shahroodut.ac.ir/article_724.html}, eprint = {https://jas.shahroodut.ac.ir/article_724_70e8def60b0539607f4789672c9b8d32.pdf} }