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These expository notes are dedicated to the study of the topology of configuration spaces of manifolds. We give detailed computations of many invariants, including the fundamental group of the configuration spaces of $\mathbb{R}^2$, the…

Algebraic Topology · Mathematics 2018-03-30 Ben Knudsen

In this paper we prove tight bounds on the combinatorial and topological complexity of sets defined in terms of $n$ definable sets belonging to some fixed definable family of sets in an o-minimal structure. This generalizes the…

Combinatorics · Mathematics 2014-02-26 Saugata Basu

We prove that the cohomology groups of a definably compact set over an o-minimal expansion of a group are finitely generated and invariant under elementary extensions and expansions of the language. We also study the cohomology of the…

Logic · Mathematics 2010-09-28 Alessandro Berarducci , Antongiulio Fornasiero

We give a description of the cohomology groups of the structure sheaf on smooth compactifications $\overline{X}(w)$ of Deligne--Lusztig varieties $X(w)$ for ${\rm GL}_n$, for all elements $w$ in the Weyl group. As a consequence, we obtain…

Algebraic Geometry · Mathematics 2024-03-18 Yingying Wang

A topological shape analysis is proposed and utilized to learn concepts that reflect shape commonalities. Our approach is two-fold: i) a spatial topology analysis of point cloud segment constellations within objects. Therein constellations…

Computer Vision and Pattern Recognition · Computer Science 2018-11-22 Christian A. Mueller , Andreas Birk

This paper continues the development of the deformation theory of abelian categories introduced in a previous paper by the authors. We show first that the deformation theory of abelian categories is controlled by an obstruction theory in…

K-Theory and Homology · Mathematics 2007-05-23 W. T. Lowen , M. Van den Bergh

We use a well known problem in discrete and computational geometry (partitions of measures by $k$-fans) as a motivation and as a point of departure to illustrate many aspects, both theoretical and computational, of the problem of…

Algebraic Topology · Mathematics 2007-05-23 Pavle V. M. Blagojevic , Sinisa T. Vrecica , Rade T. Zivaljevic

The outlines of a "Galois theory" for bimeromorphic geometry is here developed, via the study of model-theoretic definable binding groups in the theory CCM of compact complex spaces. As an application, a structure theorem about principal…

Logic · Mathematics 2025-12-15 Rahim Moosa , Anand Pillay

Scheme-theoretic methods are used to classify ternary quadratic forms with values in line bundles over arbitrary schemes and to canonically determine the isomorphisms between them. The association of a quadratic bundle to its even Clifford…

Algebraic Geometry · Mathematics 2007-05-23 Venkata Balaji Thiruvalloor Eesanaipaadi

We show that the classical homology theory of Steenrod may be enriched with descriptive set-theoretic information. We prove that the resulting definable homology theory provides a strictly finer invariant than Steenrod homology for compact…

Algebraic Topology · Mathematics 2024-04-23 Jeffrey Bergfalk , Martino Lupini , Aristotelis Panagiotopoulos

Finite-order invariants of knots in arbitrary 3-manifolds (including non-orientable ones) are constructed and studied by methods of the topology of discriminant sets. Obstructions to the integrability of admissible weight systems to…

Geometric Topology · Mathematics 2016-09-07 Victor A. Vassiliev

Multiparameter persistent homology has emerged as a powerful generalization of topological data analysis, capable of encoding multivariate filtrations. However, the algebraic complexity of multiparameter persistence modules, marked by wild…

Algebraic Topology · Mathematics 2026-04-14 Mauricio Angel

A significant group of problems coming from the realm of Combinatorial Geometry can only be approached through the use of Algebraic Topology. From the first such application to Kneser's problem in 1978 by Lov% \'{a}sz \cite{Lovasz} through…

Algebraic Topology · Mathematics 2007-05-23 Pavle V. M. Blagojevic , Aleksandra S. Dimitrijevic Blagojevic

Let $V$ be a finite dimensional complex vector space and $W\subset \GL(V)$ be a finite complex reflection group. Let $V^{\reg}$ be the complement in $V$ of the reflecting hyperplanes. A classical conjecture predicts that $V^{\reg}$ is a…

Geometric Topology · Mathematics 2007-05-23 David Bessis

A new cohomology, induced by a vector field, is defined on pairs of differential forms ($1$--differentiable forms) in a manifold. It is proved a link with the classical de Rham cohomology and an $1$-differentable cohomology of Lichnerowicz…

Differential Geometry · Mathematics 2014-06-24 Mircea Crasmareanu , Cristian Ida , Paul Popescu

Given a diagram of Pi-algebras (graded groups equipped with an action of the primary homotopy operations), we ask whether it can be realized as the homotopy groups of a diagram of spaces. The answer given here is in the form of an…

Algebraic Topology · Mathematics 2009-04-03 David Blanc , Mark W Johnson , James M Turner

Our constructions provide a systematic way to study cohomology pre-algebraic structures via classical cohomology, simplifying computations and enabling the use of established techniques.

Rings and Algebras · Mathematics 2026-04-01 H. Alhussein

We define a homotopy algebra associated to classical open-closed strings. We call it an open-closed homotopy algebra (OCHA). It is inspired by Zwiebach's open-closed string field theory and also is related to the situation of Kontsevich's…

Quantum Algebra · Mathematics 2009-11-10 Hiroshige Kajiura , Jim Stasheff

We develop the theory of probabilistic variants of the one-category and diagonal topological complexity, which bound the classical LS-category and topological complexity from below. Unlike any other classical or probabilistic invariants,…

Algebraic Topology · Mathematics 2025-12-16 Ekansh Jauhari , John Oprea

We develop in this paper the theory of covers for Hausdorff properly $\bigvee $-definable manifolds with definable choice in an o-minimal structure $\N$. In particular, we show that given an $\N$-definably connected $\N$-definable group $G$…

Logic · Mathematics 2007-05-23 Mario J. Edmundo