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Let $(\lambda^+(M),\lambda^-(M))$ denote the pair of measured foliations at the boundary at infinity $\partial_\infty$ of a quasi-Fuchsian manifold $M$. We prove that $(\lambda^+(M),\lambda^-(M))$ is filling if $M$ is close to being…

Geometric Topology · Mathematics 2025-05-08 Diptaishik Choudhury Vladimir Marković

Let $X$ be an irreducible algebraic variety over $\mathbb{C}$, endowed with an algebraic foliation ${\cal{F}}$. In this paper, we introduce the notion of minimal invariant variety $V({\cal{F}},Y)$ with respect to $({\cal{F}},Y)$, where $Y$…

Algebraic Geometry · Mathematics 2007-05-23 Philippe Bonnet

Let $M$ be a compact complex manifold admitting a K\"ahler structure. A conformally K\"ahler, Einstein-Maxwell metric (cKEM metric for short) is a Hermitian metric $\tilde{g}$ on $M$ with constant scalar curvature such that there is a…

Differential Geometry · Mathematics 2017-08-15 Akito Futaki , Hajime Ono

We show that diagrammatic sets, a topologically sound alternative to polygraphs and strict $\omega$-categories, admit an internal notion of equivalence in the sense of coinductive weak invertibility. We prove that equivalences have the…

Category Theory · Mathematics 2025-12-23 Clémence Chanavat , Amar Hadzihasanovic

The topological Molino's description of equicontinuous foliated spaces, studied by the first author and Moreira Galicia, gives conditions to reduce their study to the particular case where the holonomy pseudogroup can be represented by a…

Geometric Topology · Mathematics 2019-04-23 Jesús A. Álvarez López , Ramón Barral Lijó

Given a flat metric one may generate a local Hamiltonian structure via the fundamental result of Dubrovin and Novikov. More generally, a flat pencil of metrics will generate a local bi-Hamiltonian structure, and with additional…

Differential Geometry · Mathematics 2020-12-16 Liana David , Ian A. B. Strachan

Center foliations of partially hyperbolic diffeomorphisms may exhibit pathological behavior from a measure-theoretical viewpoint: quite often, the disintegration of the ambient volume measure along the center leaves consists of atomic…

Dynamical Systems · Mathematics 2016-03-14 Marcelo Viana , Jiagang Yang

We study minimal transverse foliations which are $R$-covered. If in addition the dimension of the ambient manifold is $3$, and the foliations are Anosov foliations we give necessary and sufficient conditions for the intersected foliation to…

Geometric Topology · Mathematics 2025-01-27 Thierry Barbot , Sergio R. Fenley , Rafael Potrie

We introduce and investigate a novel notion of transversely affine foliation, comparing and contrasting it to the previous ones in the literature. We then use it to give an extension of the classic Hadamard's theorem from Riemannian…

Differential Geometry · Mathematics 2025-03-11 Francisco C. Caramello , Henrique A. Puel Martins , Ivan P. Costa e Silva

We investigate amenability for $W^*$-Fell bundles over a discrete group $G$, with a focus on its characterization via approximation properties and conditional expectations. Building on the notion of $W^*$-amenability, we construct an…

Operator Algebras · Mathematics 2025-12-19 Alcides Buss , Damián Ferraro

In this paper we develop a notion of Gibbs measure for the geodesic flow tangent to a foliated bundle over a compact and negatively curved basis. We also develop a notion of $F$-harmonic measure and prove that there exists a natural…

Dynamical Systems · Mathematics 2016-08-24 Sébastien Alvarez

A contact pair on a manifold always admits an associated metric for which the two characteristic contact foliations are orthogonal. We show that all these metrics have the same volume element. We also prove that the leaves of the…

Differential Geometry · Mathematics 2011-10-28 Gianluca Bande , Amine Hadjar

Let $G$ be a non-amenable countable group. We show that every almost automorphic $G$-action on a compact Hausdorff space, with a maximal equicontinuous factor whose phase space is a Cantor set, admits invariant probability measures (this…

Dynamical Systems · Mathematics 2023-12-27 María Isabel Cortez , Jaime Gómez

We continue the investigation of notions of approximate amenability that were introduced in work of the second and third authors. It is shown that every boundedly approximately contractible Banach algebra has a bounded approximate identity.…

Functional Analysis · Mathematics 2009-03-26 Y. Choi , F. Ghahramani , Y. Zhang

In this short note, exploits of constructions of $\mathcal{F}$-structures coupled with technology developed by Cheeger-Gromov and Paternain-Petean are seen to yield a procedure to compute minimal entropy, minimal volume, Yamabe invariant…

Differential Geometry · Mathematics 2015-11-25 Rafael Torres

We construct a simple topological invariant of certain 3-manifolds, including quotients of the 3-sphere by finite groups, based on the fact that the tangent bundle of an orientable 3-manifold is trivialisable. This invariant is strong…

Geometric Topology · Mathematics 2007-05-23 Siddhartha Gadgil

We present a new approach to the amenability of groupoids (both in the measure theoretical and the topological setups) based on using Markov operators. We introduce the notion of an invariant Markov operator on a groupoid and show that the…

Functional Analysis · Mathematics 2007-05-23 Vadim A. Kaimanovich

In this paper, we investigate the minimization of a functional in which the usual perimeter is competing with a nonlocal singular term comparable (but not necessarily equal to) a fractional perimeter. The motivation for this problem is a…

Analysis of PDEs · Mathematics 2020-09-09 Antoine Mellet , Yijing Wu

We study harmonic and totally invariant measures in a foliated compact Riemannian manifold isometrically embedded in an Euclidean space. We introduce geometrical techniques for stochastic calculus in this space. In particular, using these…

Differential Geometry · Mathematics 2012-08-06 Pedro J. Catuogno , Diego S. Ledesma , Paulo R. Ruffino

\emph{Scalable spaces} are simply connected compact manifolds or finite complexes whose real cohomology algebra embeds in their algebra of (flat) differential forms. This is a rational homotopy invariant property and all scalable spaces are…

Geometric Topology · Mathematics 2022-09-16 Aleksandr Berdnikov , Fedor Manin