EuDML | Browse

Page 1

Displaying 1 – 11 of 11

On chirality groups and regular coverings of regular oriented hypermaps

Antonio Breda d'Azevedo, Ilda Inácio Rodrigues, Maria Elisa Fernandes (2011)

Czechoslovak Mathematical Journal

We prove that if the Walsh bipartite map $ℳ = 𝒲 (ℋ)$ of a regular oriented hypermap $ℋ$ is also orientably regular then both $ℳ$ and $ℋ$ have the same chirality group, the covering core of $ℳ$ (the smallest regular map covering $ℳ$ ) is the Walsh bipartite map of the covering core of $ℋ$ and the closure cover of $ℳ$ (the greatest regular map covered by $ℳ$ ) is the Walsh bipartite map of the closure cover of $ℋ$ . We apply these results to the family of toroidal chiral hypermaps ${(3, 3, 3)}_{b, c} = 𝒲^{- 1} {6, 3}_{b, c}$ induced by the family of toroidal bipartite maps...

On finite subgroups of groups of type VF.

Leary, Ian J. (2005)

Geometry & Topology

On groups generated by two positive multi-twists: Teichmüller curves and Lehmer's number.

Leininger, Christopher J. (2004)

Geometry & Topology

On irreducible, infinite, nonaffine Coxeter groups

Dongwen Qi (2007)

Fundamenta Mathematicae

The following results are proved: The center of any finite index subgroup of an irreducible, infinite, nonaffine Coxeter group is trivial; Any finite index subgroup of an irreducible, infinite, nonaffine Coxeter group cannot be expressed as a product of two nontrivial subgroups. These two theorems imply a unique decomposition theorem for a class of Coxeter groups. We also prove that the orbit of each element other than the identity under the conjugation action in an irreducible, infinite, nonaffine...

On the Cantor-Bendixson rank of metabelian groups

Yves Cornulier (2011)

Annales de l’institut Fourier

We study the Cantor-Bendixson rank of metabelian and virtually metabelian groups in the space of marked groups, and in particular, we exhibit a sequence $(G_{n})$ of 2-generated, finitely presented, virtually metabelian groups of Cantor-Bendixson rank $ω^{n}$ .

On the linearity problem for mapping class groups.

Brendle, Tara E., Hamidi-Tehrani, Hessam (2001)

Algebraic & Geometric Topology

On the residual properties of link groups.

Bardakov, V.G., Mikhajlov, R.V. (2007)

Sibirskij Matematicheskij Zhurnal

On the simple connectivity at infinity of groups

Daniele Ettore Otera (2003)

Bollettino dell'Unione Matematica Italiana

We study the simple connectivity at infinity of groups of finite presentation, and we give a geometric proof of its invariance under quasi-isometry in a special case.

One-relator groups and proper 3-realizability.

M. Cárdenas, F.F. Lasheras, A. Quintero, D. Repovs (2009)

Revista Matemática Iberoamericana

Optics in Croke-Kleiner Spaces

Fredric D. Ancel, Julia M. Wilson (2010)

Bulletin of the Polish Academy of Sciences. Mathematics

We explore the interior geometry of the CAT(0) spaces $X_{α} : 0 < α \leq π / 2$ , constructed by Croke and Kleiner [Topology 39 (2000)]. In particular, we describe a diffraction effect experienced by the family of geodesic rays that emanate from a basepoint and pass through a certain singular point called a triple point, and we describe the shadow this family casts on the boundary. This diffraction effect is codified in the Transformation Rules stated in Section 3 of this paper. The Transformation Rules have various applications....

OPTi's algorithm for discreteness determination.

Wada, Masaaki (2006)

Experimental Mathematics

Displaying 1 – 11 of 11

Currently displaying 1 – 11 of 11