Results 61 to 70 of about 521,410 (206)
Ecology Letters, Volume 29, Issue 2, February 2026.We use topological data analysis to reveal a persistent morphological gap in a major group of songbirds (superfamily Passeroidea). The gap remained unoccupied for millions of years, even though nearby morphologies are common and the same body form exists in other groups of birds.
Stephanie Y. Chia +4 more
wiley +1 more source
A geometry of information, I: Nerves, posets and differential forms [PDF]
, 2005 The main theme of this workshop (Dagstuhl seminar 04351) is `Spatial Representation: Continuous vs. Discrete'. Spatial representation has two contrasting but interacting aspects (i) representation of spaces' and (ii) representation by spaces.
Gratus, Jonathan, Porter, Timothy
core +5 more sources
The cosymplectic Chern–Hamilton conjecture
Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.Abstract In this paper, we study the Chern–Hamilton energy functional on compact cosymplectic manifolds, fully classifying in dimension 3 those manifolds admitting a critical compatible metric for this functional. This is the case if and only if either the manifold is co‐Kähler or if it is a mapping torus of the 2‐torus by a hyperbolic toral ...
Søren Dyhr +3 more
wiley +1 more source
The Vietoris-Rips complexes of a circle
, 2017 Given a metric space X and a distance threshold r>0, the Vietoris-Rips simplicial complex has as its simplices the finite subsets of X of diameter less than r.
Adamaszek, Michal, Adams, Henry
core +1 more source
Profinite direct sums with applications to profinite groups of type ΦR$\Phi _R$
Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.Abstract We show that the ‘profinite direct sum’ is a good notion of infinite direct sums for profinite modules, having properties similar to those of direct sums of abstract modules. For example, the profinite direct sum of projective modules is projective, and there is a Mackey's formula for profinite modules described using these sums.
Jiacheng Tang
wiley +1 more source
A Vietoris-Smale mapping theorem for the homotopy of hyperdefinable sets [PDF]
, 2017 Results of Smale (1957) and Dugundji (1969) allow to compare the homotopy groups of two topological spaces $X$ and $Y$ whenever a map $f:X\to Y$ with strong connectivity conditions on the fibers is given.
Achille, Alessandro +1 more
core +2 more sources
Topology becomes algebraic with Vietoris and Noether
Journal of Pure and Applied Algebra, 1986 The author points out that homology groups were formally introduced simultaneously by Emmy Noether and Leopold Vietoris in 1926 and produces evidence that the Göttingen and Vienna schools were independent in this achievement. He also quotes a letter from Vietoris in which the latter writes ''Without doubt H.
openaire +2 more sources
Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.Abstract We classify fibered ribbon pretzel knots up to mutation. The classification is complete, except perhaps for members of Lecuona's “exceptional” family of Lecuona [Algebr. Geom. Topol. 15 (2015), no. 4, 2133–2173]. The result is obtained by combining lattice embedding techniques with Gabai's classification of fibered pretzel knots, and ...
Ana G. Lecuona, Andy Wand
wiley +1 more source
Multiscale Cell–Cell Interactive Spatial Transcriptomics Analysis
Advanced Science, Volume 12, Issue 44, November 27, 2025.In this study, we present the MultiScale Cell‐Cell Interactive Spatial Transcriptomics Analysis method, which unites the strengths of spatially resolved deep learning techniques with a topological representation of multi‐scale cell‐cell similarity relations.
Sean Cottrell, Guo‐Wei Wei
wiley +1 more source
A short note on hit-and-miss hyperspaces
Applied General Topology, 2003 Based on some set-theoretical observations, compactness results are given for general hit-and-miss hyperspaces. Compactness here is sometimes viewed splitting into “κ-Lindelöfness” and “κ-compactness” for cardinals κ.
René Bartsch, Harry Poppe
doaj +1 more source