Search results for " branched covering"

showing 7 items of 7 documents

Irreducible components of Hurwitz spaces of coverings with two special fibers

2013

In this paper we prove new results of irreducibility for Hurwitz spaces of coverings whose monodromy group is a Weyl group of type B_d and whose local monodromies are all reflections except two.

Weyl groupPure mathematicsHurwitz quaternionGroup (mathematics)General MathematicsType (model theory)Hurwitz spaces special fibers branched coverings Weyl group of type B_d monodromy braid moves.symbols.namesakeMathematics::Algebraic GeometryMonodromyHurwitz's automorphisms theoremsymbolsIrreducibilitySettore MAT/03 - GeometriaMathematics::Representation TheoryMathematics
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On coverings with special points and monodromy group a Weyl group of type B_d

2014

In this paper we study Hurwitz spaces parameterizing coverings with special points and with monodromy group a Weyl group of type Bd. We prove that such spaces are irreducible if k > 3d ? 3. Here, k denotes the number of local monodromies that are reflections relative to long roots.

Hurwitz spacespecial fibers branched coveringWeyl groupPure mathematicsGeneral Mathematicsmonodromybraid moves.Type (model theory)Algebrasymbols.namesakeMonodromysymbolsSettore MAT/03 - GeometriaMathematics
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Hurwitz spaces of coverings with two special fibers and monodromy group a Weyl group of typeBd

2012

f! Y; where is a degree-two coverings with n1 branch points and branch locus D and f is a degree-d coverings with n2 points of simple branching and two special points whose local monodromy is given by e and q, respectively. Furthermore the covering f has monodromy group Sd and f. D /\ D fD? where D f denotes the branch locus of f . We prove that the corresponding Hurwitz spaces are irreducible under the hypothesis n2 s r dC 1.

CombinatoricsAlgebraWeyl groupsymbols.namesakeMonodromyGeneral MathematicssymbolsSettore MAT/03 - GeometriaHurwitz spaces special fibers branched coverings Weyl group of type B_d monodromy braid moves.Locus (mathematics)Branch pointMathematicsPacific Journal of Mathematics
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On the irreducibility of Hurwitz spaces of coverings with two special fibers

2012

Pure mathematicsMonodromyGeneral MathematicsIrreducibilitySettore MAT/03 - GeometriaHurwitz spaces special fibers branched coverings monodromy braid moves.Mathematics
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MR 3020148 Reviewed McMullen, C.T. Braid groups and Hodge theory. Mathematische Annalen, vol. 355 (2013), pp.893–-946. (Reviewer Francesca Vetro) 20F…

2014

In this paper, the author studies the unitary representations of the braid group and the geometric structures on moduli space that arise via the Hodge theory of cyclic branched coverings of P^1. In particular, the author is interested in the classification of certain arithmetic subgroups of U(r, s) which envelop the image of the braid group. The author investigates their connections with complex reflection groups, Teichm\"{u}lller curves, ergodic theory and problems in surface topology.

braid groups cyclic branched coverings moduli spaces.Settore MAT/03 - Geometria
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A note on coverings with special fibres and monodromy group $ S_{d}$

2012

We consider branched coverings of degree over with monodromy group , points of simple branching, special points and fixed branching data at the special points, where is a smooth connected complex projective curve of genus , and , are integers with . We prove that the corresponding Hurwitz spaces are irreducible if .

CombinatoricsProjective curveBranching (linguistics)Mathematics::Algebraic GeometryMonodromyGeneral MathematicsHigh Energy Physics::ExperimentHurwitz spaces special fibres branched coverings monodromy braid moves.Settore MAT/03 - GeometriaMathematicsIzvestiya: Mathematics
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On the classification of Kim and Kostrikin manifolds

2006

International audience; We completely classify the topological and geometric structures of some series of closed connected orientable 3-manifolds introduced by Kim and Kostrikin in [20, 21] as quotient spaces of certain polyhedral 3-cells by pairwise identifications of their boundary faces. Then we study further classes of closed orientable 3-manifolds arising from similar polyhedral schemata, and describe their topological properties.

[ MATH.MATH-GT ] Mathematics [math]/Geometric Topology [math.GT]3-manifolds; group presentations; spines; orbifolds; polyhedral schemata; branched coveringsAlgebra and Number TheorySeries (mathematics)010102 general mathematicsBoundary (topology)spines0102 computer and information sciences01 natural sciencesgroup presentations3-manifoldsCombinatoricspolyhedral schemata010201 computation theory & mathematics[MATH.MATH-GT]Mathematics [math]/Geometric Topology [math.GT]Pairwise comparisonorbifoldsbranched coverings0101 mathematicsQuotient[MATH.MATH-GT] Mathematics [math]/Geometric Topology [math.GT]Mathematics
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