English
Related papers

Related papers: Sober metric approach spaces

200 papers

The completeness properties of spaces of immersed curves equipped with reparametrization-invariant Riemannian metrics have recently been the subject of active research. This thesis studies the metric completion of spaces of immersed open…

Differential Geometry · Mathematics 2025-09-16 Ronny Gelman

We prove that for any given integer $c>0$ any metric space on $n$ points may be isometrically embedded into $l_{\infty}^{n-c}$ provided $n$ is large enough.

Combinatorics · Mathematics 2014-01-14 Fedor Petrov , Dmitri Stolyarov , Pavel Zatitskiy

We study completeness properties of Sobolev metrics on the space of immersed curves and on the shape space of unparametrized curves. We show that Sobolev metrics of order $n\geq 2$ are metrically complete on the space $\mathcal…

Differential Geometry · Mathematics 2015-04-09 Martins Bruveris

A metric space X is straight if for each finite cover of X by closed sets, and for each real valued function f on X, if f is uniformly continuous on each set of the cover, then f is uniformly continuous on the whole of X. A locally…

General Topology · Mathematics 2008-10-01 Alessandro Berarducci , Dikran Dikranjan , Jan Pelant

In a spherically complete ultrametric space, a strictly contracting mapping has a fixed point. We indicate in this paper how this fixed point can either be reached or approximated.

Metric Geometry · Mathematics 2013-07-25 Sibylla Priess-Crampe , Paulo Ribenboim

We investigate some versions of $d$-space, well-filtered space and Rudin space concerning various countability properties. The main results include: (i) if the sobrification of a $T_0$ space $X$ is first-countable, then $X$ is an…

General Topology · Mathematics 2020-08-26 Xiaoquan Xu , Chong Shen , Xiaoyong Xi , Dongsheng Zhao

Let $M$ be a topological spherical space form, i.e. a smooth manifold whose universal cover is a homotopy sphere. We determine the number of path components of the space and moduli space of Riemannian metrics with positive scalar curvature…

Differential Geometry · Mathematics 2020-02-20 Philipp Reiser

We show that for generic sliced spacetimes global hyperbolicity is equivalent to space completeness under the assumption that the lapse, shift and spatial metric are uniformly bounded. This leads us to the conclusion that simple sliced…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Spiros Cotsakis

A cylindrically symmetric perfect fluid spacetime with no curvature singularity is shown. The equation of state for the perfect fluid is that of a stiff fluid. The metric is diagonal and non-separable in comoving coordinates for the fluid.…

General Relativity and Quantum Cosmology · Physics 2009-11-10 L. Fernandez-Jambrina

M. Escard\'o et al. asked whether the core compactly generated topology of a sober space is again sober and the sobrification of a core compactly generated space again core compactly generated. In this note, we answer the problem by…

General Topology · Mathematics 2023-05-02 Qingguo Li , Hualin Miao

We say that a metric graph is uniformly bounded if the degrees of all vertices are uniformly bounded and the lengths of edges are pinched between two positive constants; a metric space is approximable by a uniform graph if there is one…

Metric Geometry · Mathematics 2013-06-25 Dmitri Burago , Sergei Ivanov

We show that under certain mild conditions, a metric simplicial complex which satisfies the Ptolemy inequality is a CAT(0) space. Ptolemy's inequality is closely related to inversions of metric spaces. For a large class of metric simplicial…

Metric Geometry · Mathematics 2015-05-13 S. M. Buckley , J. McDougall , D. J. Wraith

We study the space of Riemannian metrics over a compact manifold equipped with the Ebin metric. We characterize its self-isometries and prove that two such spaces are isometric if and only if their underlying manifolds are diffeomorphic.

Metric Geometry · Mathematics 2025-12-09 David Lenze

We construct a metric space whose transfinite asymptotic dimension and complementary-finite asymptotic dimension $2\omega+1$.

General Topology · Mathematics 2020-04-29 Yan Wu , Jingming Zhu

We consider sets in uniformly perfect metric spaces which are null for every doubling measure of the space or which have positive measure for all doubling measures. These sets are called thin and fat, respectively. In our main results, we…

Classical Analysis and ODEs · Mathematics 2012-04-27 Tuomo Ojala , Tapio Rajala , Ville Suomala

A base $\mathcal{B}$ for a space $X$ is said to be sharp if, whenever $x\in X$ and $(B_n)_{n\in\omega}$ is a sequence of pairwise distinct elements of $\mathcal{B}$ each containing $x$, the collection $\{\bigcap_{j\le n}B_j:n\in\omega\}$ is…

General Topology · Mathematics 2007-05-23 Chris Good , Robin W. Knight , Abdul M. Mohamad

A metric measure space $(X,\mu)$ is 1-regular if \[0< \lim_{r\to 0} \frac{\mu(B(x,r))}{r}<\infty\] for $\mu$-a.e $x\in X$. We give a complete geometric characterisation of the rectifiable and purely unrectifiable part of a 1-regular measure…

Metric Geometry · Mathematics 2025-01-13 David Bate

We find necessary and sufficient conditions under which an arbitrary metric space $X$ has a unique pretangent space at the marked point $a\in X$. Key words: Metric spaces; Tangent spaces to metric spaces; Uniqueness of tangent metric…

Metric Geometry · Mathematics 2009-03-27 Oleksiy Dovgoshey , Fahreddin Abdullayev , Mehmet Kuchukaslan

We prove that the Lipschitz-free space over any uniformly discrete metric space has the 3-Schur property

Functional Analysis · Mathematics 2026-04-03 Marek Cúth , Ondřej F. K. Kalenda

We make a systematic study of frames for metric spaces. We prove that every separable metric space admits a metric $\mathcal{M}_d$-frame. Through Lipschitz-free Banach spaces we show that there is a correspondence between frames for metric…

Functional Analysis · Mathematics 2020-11-04 K. Mahesh Krishna , P. Sam Johnson