163 Result(s)

Article

The strong Novikov conjecture for low degree cohomology

We show that for each discrete group Γ, the rational assembly map $$K_*(B\Gamma) \otimes {\mathbb{Q}} \to K_*(C^*_{\max}\Gamma) \otimes {\math...

Bernhard Hanke, Thomas Schick in Geometriae Dedicata (2008)

Article

Equivariant plateau problems

Let (M, Q) be a compact, three dimensional manifold of strictly negative sectional curvature. Let (Σ, P) be a compact, orientable surface of hyperbolic type (i.e. of genus at least two). Let θ : π₁(Σ, P) → π₁(M,

Graham Smith in Geometriae Dedicata (2009)

Article

L’application cotangente des surfaces de type général

We study surfaces of general type S whose cotangent sheaf is generated by its global sections. We define a map called the cotangent map of S that enables us to understand the obstructions to the ampleness of the ...

Xavier Roulleau in Geometriae Dedicata (2009)

Article

Knots and k-width

We investigate several natural invariants of curves and knots in \({\mathbb{R}^3}\) . These invariants generalize bridge number...

Joel Hass, J. Hyam Rubinstein, Abigail Thompson in Geometriae Dedicata (2009)

Article

Infinite genus surfaces and irrational polygonal billiards

We prove that the natural invariant surface associated with the billiard game on an irrational polygonal table is homeomorphic to the Loch Ness monster, that is, the only orientable infinite genus topological ...

Ferrán Valdez in Geometriae Dedicata (2009)

Article

A family of non-isomorphism results

We calculate the local groups of germs associated with the higher dimensional R. Thompson groups nV. For a given $${n\in N\cup\left\{\...

Collin Bleak, Daniel Lanoue in Geometriae Dedicata (2010)

Article

Perelman’s \({\bar{\lambda}}\) -invariant and collapsing via geometric characteristic splittings

Any closed, orientable, smooth, nonpositively curved manifold M is known to admit a geometric characteristic splitting, analogous to the JSJ decomposition in three dimensions. We show that when this splitting con...

P. Suárez-Serrato in Geometriae Dedicata (2010)

Article

Limits of dihedral groups

We characterise limits of dihedral groups in the space of finitely generated marked groups. We also describe the topological closure of dihedral groups in the space of marked groups on a fixed number of genera...

Luc Guyot in Geometriae Dedicata (2010)

Article

Ford fundamental domains in symmetric spaces of rank one

We show the existence of isometric (or Ford) fundamental regions for a large class of subgroups of the isometry group of any rank one Riemannian symmetric space of noncompact type. The proof does not use the c...

Anke D. Pohl in Geometriae Dedicata (2010)

Article

Blocks of monodromy groups in complex dynamics

Motivated by a problem in complex dynamics, we examine the block structure of the natural action of iterated monodromy groups on the tree of preimages of a generic point. We show that in many cases, including ...

Rafe Jones, Han Peters in Geometriae Dedicata (2011)

Article

Ruled quartic surfaces, models and classification

New historical aspects of the classification, by Cayley and Cremona, of ruled quartic surfaces and the relation to string models and plaster models are presented. In a ‘modern’ treatment of the classification ...

Irene Polo-Blanco, Marius van der Put, Jaap Top in Geometriae Dedicata (2011)

Article

Spherical complexes attached to symplectic lattices

To the integral symplectic group \({{\rm Sp}(2g,\mathbb{Z})}\) we associate two posets of which we prove that they ha...

Wilberd van der Kallen, Eduard Looijenga in Geometriae Dedicata (2011)

Article

Conformality of a differential with respect to Cheeger-Gromoll type metrics

We investigate conformality of the differential of a map** between Riemannian manifolds if the tangent bundles are equipped with a generalized metric of Cheeger-Gromoll type.

Wojciech Kozłowski, Kamil Niedziałomski in Geometriae Dedicata (2012)

Article

Insecurity for compact surfaces of positive genus: commentary

Victor Bangert, Eugene Gutkin in Geometriae Dedicata (2012)

Article

Crosscap slides and the level 2 map** class group of a nonorientable surface

Crosscap slide is a homeomorphism of a nonorientable surface of genus at least 2, which was introduced under the name Y-homeomorphism by Lickorish as an example of an element of the map** class group which c...

Błażej Szepietowski in Geometriae Dedicata (2012)

Article

Asymptotic dimension and small subsets in locally compact topological groups

We prove that for a coarse space \(X\) the ideal ...

Taras Banakh, Ostap Chervak, Nadya Lyaskovska in Geometriae Dedicata (2014)

Article

A Lefschetz duality for intersection homology

We prove a Lefschetz duality theorem for intersection homology. Usually, this result applies to pseudomanifolds with boundary which are assumed to have a “collared neighborhood of their boundary”. Our duality ...

Guillaume Valette in Geometriae Dedicata (2014)

Article

Singularities of equidistants and global centre symmetry sets of Lagrangian submanifolds

We study the global centre symmetry set (GCS) of a smooth closed submanifold \(M^m\subset \mathbb{R }^n, n \le 2m\) . ...

Wojciech Domitrz, Pedro de M. Rios in Geometriae Dedicata (2014)

Article

Generalized symplectic symmetric spaces

Bieliavsky introduced and investigated a class of symplectic symmetric spaces, that is, symmetric spaces endowed with a symplectic structure invariant with respect to symmetries. The theory of symmetric spaces...

Maciej Bocheński, Aleksy Tralle in Geometriae Dedicata (2014)

Article

Invariance of finiteness of K-area under surgery

K-area is an invariant for Riemannian manifolds introduced by Gromov as an obstruction to the existence of positive scalar curvature. However in general it is difficult to determine whether K-area is finite or...

Yoshiyasu Fukumoto in Geometriae Dedicata (2015)