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Remarques à propos d'un lemme de R.H. Fox, le groupe fondamental d'un revêtement ramifié

Michel Domergue (1978)

Annales de l'institut Fourier

Dans cette note, nous reformulons et nous démontrons un lemme dont l’énoncé et la démonstration donnés dans un article de R.H. Fox sur les revêtements ramifiés, comportent un certain nombre d’imprécisions. Nous établissons aussi deux théorèmes qui sont utilisés pour calculer le groupe fondamental de l’antécédent, au sens de Fox, d’un revêtement ramifié lorsque celui-ci est un complexe homogène sans bord de dimension 3 ou une n -variété combinatoire sans bord.

Representation of finite groups and the first Betti number of branched coverings of a universal Borromean orbifold

Masahito Toda (2004)

Open Mathematics

The paper studies the first homology of finite regular branched coverings of a universal Borromean orbifold called B 4,4,4ℍ3. We investigate the irreducible components of the first homology as a representation space of the finite covering transformation group G. This gives information on the first betti number of finite coverings of general 3-manifolds by the universality of B 4,4,4. The main result of the paper is a criterion in terms of the irreducible character whether a given irreducible representation...

Representations of (1,1)-knots

Alessia Cattabriga, Michele Mulazzani (2005)

Fundamenta Mathematicae

We present two different representations of (1,1)-knots and study some connections between them. The first representation is algebraic: every (1,1)-knot is represented by an element of the pure mapping class group of the twice punctured torus PMCG₂(T). Moreover, there is a surjective map from the kernel of the natural homomorphism Ω:PMCG₂(T) → MCG(T) ≅ SL(2,ℤ), which is a free group of rank two, to the class of all (1,1)-knots in a fixed lens space. The second representation is parametric: every...

Representations of the Kauffman bracket skein algebra of the punctured torus

Jea-Pil Cho, Răzvan Gelca (2014)

Fundamenta Mathematicae

We describe the action of the Kauffman bracket skein algebra on some vector spaces that arise as relative Kauffman bracket skein modules of tangles in the punctured torus. We show how this action determines the Reshetikhin-Turaev representation of the punctured torus. We rephrase our results to describe the quantum group quantization of the moduli space of flat SU(2)-connections on the punctured torus with fixed trace of the holonomy around the boundary.

Representing open 3-manifolds as 3-fold branched coverings.

José María Montesinos-Amilibia (2002)

Revista Matemática Complutense

It is proved that the Freudenthal compactification of an open, connected, oriented 3-manifold is a 3-fold branched covering of S3, and in some cases, a 2-fold branched covering of S3. The branching set is a locally finite disjoint union of strings.

Currently displaying 21 – 40 of 51