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For a finite, positive, Borel measure $\mu$ on $(0,1)$ we consider an infinite matrix $\Gamma_\mu$, related to the classical Hausdorff matrix defined by the same measure $\mu$, in the same algebraic way that the Hilbert matrix is related to…

Functional Analysis · Mathematics 2025-06-13 Carlo Bellavita , Nikolaos Chalmoukis , Vassilis Daskalogiannis , Georgios Stylogiannis

If X is a proper CAT(-1)-space and $\Gamma$ a non-elementary discrete group of isometries acting properly discontinuously on X, it is shown that the geodesic flow on the quotient space Y=X/$\Gamma$ is topologically mixing, provided that the…

Geometric Topology · Mathematics 2018-11-28 Ch. Charitos , G. Tsapogas

In this paper we study of the structure of non-commutative Poisson algebras with an arbitrary set $\ss.$ We show that any of such an algebra $\pp$ decomposes as…

Rings and Algebras · Mathematics 2023-04-13 Valiollah Khalili

Standard results in descriptive set theory provide sufficient conditions for a Borel set $P \subseteq \mathbb{N}^\mathbb{N} \times \mathbb{N}^\mathbb{N}$ to admit a Borel uniformization, namely, when $P$ has "small" sections or "large"…

Logic · Mathematics 2025-08-26 Alexander S. Kechris , Michael Wolman

We continue the work of [1, 2, 3] by analyzing the equivalence relation of bi-embeddability on various classes of countable planes, most notably the class of countable non-Desarguesian projective planes. We use constructions of the second…

Logic · Mathematics 2020-10-16 Filippo Calderoni , Gianluca Paolini

This paper concerns the compactness and separability properties of the normed Boolean algebras (N.B.A.) with respect to topology generated by a distance equal to the square root of a measure of symmetric difference between two elements. The…

General Topology · Mathematics 2022-02-08 Vesna Gotovac Đogaš

The halfspace depth of a $d$-dimensional point $x$ with respect to a finite (or probability) Borel measure $\mu$ in $\mathbb{R}^d$ is defined as the infimum of the $\mu$-masses of all closed halfspaces containing $x$. A natural question is…

Statistics Theory · Mathematics 2022-08-09 Petra Laketa , Stanislav Nagy

The Ghahramani-Lau conjecture is established; in other words, the measure algebra of every locally compact group is strongly Arens irregular. To this end, we introduce and study certain new classes of measures (called approximately…

Functional Analysis · Mathematics 2016-09-15 Viktor Losert , Matthias Neufang , Jan Pachl , Juris Steprāns

In this work we analyze the concept of swap-invariance, which is a weaker variant of exchangeability. A random vector $\xi$ in $\mathbb{R}^n$ is called swap-invariant if $\,{\mathbf E}\,\big| \!\sum_j u_j \xi_j \big|\,$ is invariant under…

Probability · Mathematics 2016-07-06 Felix Nagel

Plausibility measures are structures for reasoning in the face of uncertainty that generalize probabilities, unifying them with weaker structures like possibility measures and comparative probability relations. So far, the theory of…

Quantum Physics · Physics 2015-05-07 Tobias Fritz , Matthew Leifer

We obtain some simple relations between decomposition numbers of quantized Schur algebras at an n-th root of unity (over a field of characteristic 0). These relations imply that every decomposition number for such an algebra occurs as a…

Quantum Algebra · Mathematics 2007-05-23 Bernard Leclerc

We show for very general classes of measures on locally compact second countable groups that every Borel measurable quasimorphism is at bounded distance from a quasi-biharmonic one. This allows us to deduce non-degenerate central limit…

Group Theory · Mathematics 2015-03-17 Michael Björklund , Tobias Hartnick

The assignment of local observables in the vacuum sector, fulfilling the standard axioms of local quantum theory, is known to determine uniquely a compact group G of gauge transformations of the first kind together with a central involutive…

High Energy Physics - Theory · Physics 2016-09-06 Sergio Doplicher , Gherardo Piacitelli

We show that every basis for the countable Borel equivalence relations strictly above $\mathbb{E}_0$ under measure reducibility is uncountable, thereby ruling out natural generalizations of the Glimm-Effros dichotomy. We also push many…

Logic · Mathematics 2020-02-25 Clinton T. Conley , Benjamin D. Miller

The space of Lascar strong types, on some sort and relative to a given first order theory T, is in general not a compact Hausdorff space. This paper has at least three aims. First to show that spaces of Lascar strong types and other related…

Logic · Mathematics 2012-04-17 Krzysztof Krupinski , Anand Pillay , Slawomir Solecki

Let $B$ be a separable $C^*$-algebra, let $\Gamma$ be a discrete countable group, let $\alpha: \Gamma \to \text{Aut}(B)$ be an action, and let $A$ be an invariant subalgebra. We find certain freeness conditions which guarantee that any…

Operator Algebras · Mathematics 2023-11-06 Tattwamasi Amrutam , Ilan Hirshberg , Apurva Seth

The regular open subsets of a topological space form a Boolean algebra, where the `join' of two regular open sets is the interior of the closure of their union. A `credence' is a finitely additive probability measure on this Boolean…

General Topology · Mathematics 2021-04-30 Marcus Pivato , Vassili Vergopoulos

This article is concerned with measure equivalence and uniform measure equivalence of locally compact, second countable groups. We show that two unimodular, locally compact, second countable groups are measure equivalent if and only if they…

Group Theory · Mathematics 2019-11-19 Juhani Koivisto , David Kyed , Sven Raum

Let \Gamma be a lattice in G=SL(n,R) and X=G/S a homogeneous space of G, where S is a closed subgroup of G which contains a real algebraic subgroup H such that G/H is compact. We establish uniform distribution of orbits of \Gamma in X…

Dynamical Systems · Mathematics 2007-05-23 Alexander Gorodnik

Consider a topological dynamical system where the group is abelian and the topologies are locally compact and second-countable. Given an invariant measure for this system, we show that if its dynamical spectrum is contained in some Borel…

Dynamical Systems · Mathematics 2026-01-12 Michael Francis , Christopher Ramsey , Nicolae Strungaru