English
Related papers

Related papers: Lacunary sections for locally compact groupoids

200 papers

We equip the product of countably many copies of a compact Abelian group X with the uniform topology, and study some properties of the topological group G thus obtained. In particular, we determine the cardinality of the dual group of G,…

General Topology · Mathematics 2013-06-03 D. Dikranjan , E. Martín-Peinador , V. Tarieladze

Let $S$ be a closed surface of genus $g\geq 2$, furnished with a Borel probability measure $\lambda$ with total support. We show that if $f$ is a $\lambda$-preserving homeomorphism isotopic to the identity such that the rotation vector…

Dynamical Systems · Mathematics 2023-11-02 Pierre-Antoine Guihéneuf , Patrice Le Calvez , Alejandro Passeggi

We prove the existence of at least $cl(M)$ periodic orbits for certain time dependant Hamiltonian systems on the cotangent bundle of an arbitrary compact manifold $M$. These Hamiltonians are not necessarily convex but they satisfy a certain…

Dynamical Systems · Mathematics 2008-02-03 Christopher Golé

This paper concerns the characterisation of second order marginals for random sets in a discrete setting. Under the instance of unit covariances, this problem possesses a combinatorial symmetry, exploited jointly in the companion paper to…

Probability · Mathematics 2013-01-21 Raphael Lachieze-Rey

It is shown that CH implies the existence of a compact Hausdorff space that is countable dense homogeneous, crowded and does not contain topological copies of the Cantor set. This contrasts with a previous result by the author which says…

General Topology · Mathematics 2020-01-20 Rodrigo Hernández-Gutiérrez

The problem in question is whether the quotient space of a compact linear group is a topological manifold and whether it is a homological manifold. In the paper, the case of an infinite group with commutative connected component is…

Algebraic Geometry · Mathematics 2016-07-26 O. G. Styrt

A number of compactifications familiar in complex-analytic geometry, in particular, the Baily-Borel compactification and its toroidal variants, as well as the Deligne-Mumford compactifications, can be covered by open subsets whose nonempty…

Algebraic Topology · Mathematics 2015-11-06 Jiaming Chen , Eduard Looijenga

Results of Liflyand and collaborators on the boundedness of Hausdorff operators on the Hardy space $H^1$ over finite-dimensional real space generalized to the case of locally compact groups that are spaces of homogeneous type. Special cases…

Functional Analysis · Mathematics 2020-11-24 Adolf Mirotin

It is proved that, on any Abelian group of infinite cardinality ${\bf m}$, there exist precisely $2^{2^{\bf m}}$ nonequivalent bounded Hausdorff group topologies. Under the continuum hypothesis, the number of nonequivalent compact and…

Group Theory · Mathematics 2016-10-04 I. K. Babenko , S. A. Bogatyi

This paper is the second in a series exploring the properties of a functor which assigns a homotopy double groupoid with connections to a Hausdorff space. We show that this functor satisfies a version of the van Kampen theorem, and so is a…

Algebraic Topology · Mathematics 2007-05-23 R. Brown , H. K. Kamps , T. Porter

In this paper, continuous binary operations of a topological space are studied and a criterion of their invertibility is proved. The classification problem of groups of invertible continuous binary operations of locally compact and locally…

General Topology · Mathematics 2023-08-01 Pavel S. Gevorgyan

We show that the topology of pointwise convergence on scattered spaces is compatible with the group structure of their homeomorphism group. We then establish a few topological properties of the homeomorphism group of the first uncountable…

Group Theory · Mathematics 2020-12-02 Maxime Gheysens

If $G$ is a second countable locally compact Hausdorff groupoid with Haar system, we show that every representation induced from an irreducible representation of a stability group is irreducible.

Operator Algebras · Mathematics 2008-06-05 Marius Ionescu , Dana P. Williams

In this paper we construct faithful representations of saturated fusion systems over discrete p-toral groups and use them to find conditions that guarantee the existence of unitary embeddings of p-local compact groups. These conditions hold…

Algebraic Topology · Mathematics 2018-07-16 José Cantarero , Natàlia Castellana

We extend to metrizable locally compact groups Rosenthal's theorem describing those Banach spaces containing no copy of $l_1$. For that purpose, we transfer to general locally compact groups the notion of interpolation ($I_0$) set, which…

General Topology · Mathematics 2018-04-03 Marita Ferrer , Salvador Hernández , Luis Tárrega

We investigate what it means for a (Hausdorff, second-countable) topological group to be computable. We compare several potential definitions in the literature. We relate these notions with the well-established definitions of effective…

Logic · Mathematics 2025-04-16 Heer Tern Koh , Alexander Melnikov , Keng Meng Ng

We state that any constant curvature Riemannian metric with conical singularities of constant sign curvature on a compact (orientable) surface $S$ can be realized as a convex polyhedron in a Riemannian or Lorentzian) space-form. Moreover…

Differential Geometry · Mathematics 2010-11-16 François Fillastre

In this article we consider a restricted orbital counting problem for the action of certain discrete groups on suitable spaces. In particular, we present asymptotics for counting those points in an orbit restricted to a single conjugacy…

Dynamical Systems · Mathematics 2026-05-08 Alexander Baumgartner , Mark Pollicott

According to a folklore characterization of supercompact spaces, a compact Hausdorff space is supercompact if and only if it has a binary closed $k$-network. This characterization suggests to call a topological space $super$ if it has a…

General Topology · Mathematics 2020-04-09 Taras Banakh , Zdzisław Kosztołowicz , Sławomir Turek

We show that the homeomorphism group of a surface without boundary does not admit a Hausdorff group topology strictly coarser than the compact-open topology. In combination with known automatic continuity results, this implies that the…

Geometric Topology · Mathematics 2022-11-08 J. de la Nuez González