{ "id": "2303.09804", "version": "v1", "published": "2023-03-17T07:19:15.000Z", "updated": "2023-03-17T07:19:15.000Z", "title": "Commutator subgroups and crystallographic quotients of virtual extensions of symmetric groups", "authors": [ "Pravin Kumar", "Tushar Kanta Naik", "Neha Nanda", "Mahender Singh" ], "comment": "29 pages", "categories": [ "math.GR", "math.GT" ], "abstract": "The virtual braid group $VB_n$, the virtual twin group $VT_n$ and the virtual triplet group $VL_n$ are extensions of the symmetric group $S_n$, which are motivated by the Alexander-Markov correspondence for virtual knot theories. The kernels of natural epimorphisms of these groups onto the symmetric group $S_n$ are the pure virtual braid group $VP_n$, the pure virtual twin group $PVT_n$ and the pure virtual triplet group $PVL_n$, respectively. In this paper, we investigate commutator subgroups, pure subgroups and crystallographic quotients of these groups. We derive explicit finite presentations of the pure virtual triplet group $PVL_n$, the commutator subgroup $VT_n^{'}$ of $VT_n$ and the commutator subgroup $VL_n^{'}$ of $VL_n$. Our results complete the understanding of these groups, except that of $VB_n^{'}$, for which the existence of a finite presentations is not known for $n \\ge 4$. We also prove that $VL_n/PVL_n^{'}$ is a crystallographic group and give an explicit construction of infinitely many torsion elements in it.", "revisions": [ { "version": "v1", "updated": "2023-03-17T07:19:15.000Z" } ], "analyses": { "subjects": [ "20F55", "20H15", "20F36" ], "keywords": [ "commutator subgroup", "symmetric group", "crystallographic quotients", "pure virtual triplet group", "virtual extensions" ], "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable" } } }