Crystallographic groups and flat manifolds from surface braid groups

Autor: Daciberg Lima Gonçalves, John Guaschi, Oscar Ocampo, Carolina de Miranda e Pereiro
Přispěvatelé: Universidade de São Paulo (USP), Instituto de Matemática e Estatística (IME), Laboratoire de Mathématiques Nicolas Oresme (LMNO), Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), Université de Caen Normandie (UNICAEN), Normandie Université (NU), Centre National de la Recherche Scientifique (CNRS), Universidade Federal da Bahia (UFBA), Universidade Federal do Espirito Santo (UFES)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Journal of Algebra
Journal of Algebra, Elsevier, 2021, 293, pp.107560. ⟨10.1016/j.topol.2020.107560⟩
ISSN: 0021-8693
1090-266X
DOI: 10.1016/j.topol.2020.107560⟩
Popis: Let M be a compact surface without boundary, and n ≥ 2 . We analyse the quotient group B n ( M ) / Γ 2 ( P n ( M ) ) of the surface braid group B n ( M ) by the commutator subgroup Γ 2 ( P n ( M ) ) of the pure braid group P n ( M ) . If M is different from the 2-sphere S 2 , we prove that B n ( M ) / Γ 2 ( P n ( M ) ) ≅ P n ( M ) / Γ 2 ( P n ( M ) ) ⋊ φ S n , and that B n ( M ) / Γ 2 ( P n ( M ) ) is a crystallographic group if and only if M is orientable. If M is orientable, we prove a number of results regarding the structure of B n ( M ) / Γ 2 ( P n ( M ) ) . We characterise the finite-order elements of this group, and we determine the conjugacy classes of these elements. We also show that there is a single conjugacy class of finite subgroups of B n ( M ) / Γ 2 ( P n ( M ) ) isomorphic either to S n or to certain Frobenius groups. We prove that crystallographic groups whose image by the projection B n ( M ) / Γ 2 ( P n ( M ) ) ⟶ S n is a Frobenius group are not Bieberbach groups. Finally, we construct a family of Bieberbach subgroups G ˜ n , g of B n ( M ) / Γ 2 ( P n ( M ) ) of dimension 2 n g and whose holonomy group is the finite cyclic group of order n, and if X n , g is a flat manifold whose fundamental group is G ˜ n , g , we prove that it is an orientable Kahler manifold that admits Anosov diffeomorphisms.
Databáze: OpenAIRE