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Related papers: Another view of the coarse invariant $\sigma$

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Let $X=(X(n))_{n \in \mathbb{Z_+}}$ be a standard subproduct system of $C^*$-correspondences over a $C^*$-algebra $\mathcal M.$ Assume $T=(T_n)_{n \in \mathbb{Z_+}}$ to be a pure completely contractive, covariant representation of $X$ on a…

Operator Algebras · Mathematics 2018-06-12 Jaydeb Sarkar , Harsh Trivedi , Shankar Veerabathiran

Let X be a G-space such that the orbit space X/G is metrizable. Suppose a family of slices is given at each point of X. We study a construction which associates, under some conditions on the family of slices, with any metric on X/G an…

Geometric Topology · Mathematics 2016-09-07 Boguslaw Hajduk , Rafal Walczak

Let $\gamma$ be a filling curve on a topological surface $\Sigma$ of genus $g \geq 2$. The inf invariant of $\gamma$, denoted $m_{\gamma}$, is the infimum of the length function on the space of marked hyperbolic structures on $\Sigma$. This…

Geometric Topology · Mathematics 2025-08-13 Ara Basmajian , Sayantika Mondal

A metric algebra is a metric variant of the notion of $\Sigma$-algebra, first introduced in universal algebra to deal with algebras equipped with metric structures such as normed vector spaces. In this paper, we showed metric versions of…

Logic · Mathematics 2017-03-13 Wataru Hino

Assume that X is a metrizable separable space, and each clopen-valued lower semicontinuous multivalued map Phi from X to Q has a continuous selection. Our main result is that in this case, X is a sigma-space. We also derive a partial…

General Topology · Mathematics 2011-08-08 Dušan Repovš , Boaz Tsaban , Lyubomyr Zdomskyy

Let $X$ be a Hausdorff topological vector space, $X^*$ its topological dual and $Z$ a subset of $X^*$. In this paper, we establish some results concerning the $\sigma(X,Z)$-approximate fixed point property for bounded, closed convex subsets…

Functional Analysis · Mathematics 2012-07-19 Cleon S. Barroso , Ondřej F. K. Kalenda , Pei-Kee Lin

Let $\mathcal{H}$ be Hilbert space and $(\Omega,\mu)$ a $\sigma$-finite measure space. Multiplicatively invariant (MI) spaces are closed subspaces of $ L^2(\Omega, \mathcal{H})$ that are invariant under point-wise multiplication by…

Classical Analysis and ODEs · Mathematics 2016-09-12 Carlos Cabrelli , Carolina A. Mosquera , Victoria Paternostro

We introduce a notion of equivariant coarse cohomology of the complement of a subspace in a metric space. We use this cohomology to define a notion of coarse cohomology of the configuration space of a metric space and develop tools to…

Metric Geometry · Mathematics 2025-11-05 Arka Banerjee

To a metric space $X$ we associate a compact topological space $\nu' X$ called the corona of $X$. Then a coarse map $f:X\to Y$ between metric spaces is mapped to a continuous map $\nu' f:\nu' X\to \nu' Y$ between coronas. Sheaf cohomology…

Metric Geometry · Mathematics 2019-04-02 Elisa Hartmann

Let $(X,T)$ and $(Y,S)$ be two topological dynamical systems, where $(X,T)$ has the weak specification property. Let $\xi$ be an invariant measure on the product system $(X\times Y, T\times S)$ with marginals $\mu$ on $X$ and $\nu$ on $Y$,…

Dynamical Systems · Mathematics 2024-11-20 Tomasz Downarowicz , Benjamin Weiss

Motivated by recently explored examples, we undertake a systematic study of conformal invariance in one-dimensional sigma models where an isometry group has been gauged. Perhaps surprisingly, we uncover classes of sigma models which are…

High Energy Physics - Theory · Physics 2023-04-05 Delaram Mirfendereski , Joris Raeymaekers , Canberk Şanlı , Dieter Van den Bleeken

A coarse space $X$, endowed with a linear order compatible with the coarse structure of $X$, is called linearly ordered. We prove that every linearly ordered coarse space $X$ is locally convex and the asymptotic dimension of $X$ is either…

General Topology · Mathematics 2021-10-05 Igor Protasov

We introduce the metric space valued in partially ordered groups, and define the convergence of sequences and the multi-valued weak contractions, etc., on the space. We then establish endpoint theorems for the defined maps. Our…

Functional Analysis · Mathematics 2014-06-03 Congdian Cheng

We consider families of geometries of D--dimensional space, described by a finite number of parameters. Starting from the De Witt metric we extract a unique integration measure which turns out to be a geometric invariant, i.e. independent…

High Energy Physics - Theory · Physics 2009-10-30 Pietro Menotti , Pier Paolo Peirano

A topological space $X$ is called strongly $\sigma$-metrizable if $X=\bigcup_{n\in\omega}X_n$ for an increasing sequence $(X_n)_{n\in\omega}$ of closed metrizable subspaces such that every convergence sequence in $X$ is contained in some…

General Topology · Mathematics 2016-11-17 Taras Banakh

In the class of metrics of a generic conformal structure there exists a distinguishing metric. This was noticed by Albert Einstein in a lesser-known paper of 1921 (Berl. Ber., 1921, pp. 261-264). We explore this finding from a geometrical…

Differential Geometry · Mathematics 2017-10-03 Ignacio Sánchez-Rodríguez

We give precise estimates of some holomorphically invariant infinitesimal metrics near a pseudoconcave points in a wide family of ``model'' domains for that situation in $\mathbb C^2$. This extends to metrics (rather distances) the authors'…

Complex Variables · Mathematics 2026-05-05 Pascal J. Thomas , Nikolai Nikolov

This paper studies the homotopy invariant $\cat(X,\xi)$ introduced in \cite{farbe2}. Given a finite cell-complex $X$, we study the function $\xi\mapsto \cat(X,\xi)$ where $\xi$ varies in the cohomology space $H^1(X;\R)$. Note that…

Algebraic Topology · Mathematics 2014-11-11 Michael Farber , Dirk Schuetz

A finitely-additive measure $\lambda $ on an infinite-dimensional real Hilbert space $E$ which is invariant with respect to shifts and orthogonal mappings has been defined. This measure can be considered as the analog of the Lebesgue…

Functional Analysis · Mathematics 2021-09-28 Vsevolod Sakbaev

We define coarse proximity structures, which are an analog of small-scale proximity spaces in the large-scale context. We show that metric spaces induce coarse proximity structures, and we construct a natural small-scale proximity…

Metric Geometry · Mathematics 2024-04-16 Pawel Grzegrzolka , Jeremy Siegert