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Related papers: Homotopy Groups and Puppe Sequence of Digraphs

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We introduce a homotopy theory of digraphs (directed graphs) and prove its basic properties, including the relations to the homology theory of digraphs constructed by the authors in previous papers. In particular, we prove the homotopy…

Algebraic Topology · Mathematics 2014-07-02 Alexander Grigor'yan , Yong Lin , Yuri Muranov , Shing-Tung Yau

We develop a homotopy theory of directed graphs based on cubical homotopy groups, also referred to as A-groups or reduced GLMY homotopy groups. Localizing the category of directed graphs at morphisms that induce isomorphisms on these groups…

Algebraic Topology · Mathematics 2026-05-07 Briony Eldridge , Sergei O. Ivanov , Xiaomeng Xu , Shing-Tung Yau , Mengmeng Zhang

We define and study homotopy groups of cubical sets. To this end, we give four definitions of homotopy groups of a cubical set, prove that they are equivalent, and further that they agree with their topological analogues via the geometric…

Algebraic Topology · Mathematics 2025-12-23 Daniel Carranza , Chris Kapulkin

Discrete homotopy theory or A-homotopy theory is a combinatorial homotopy theory defined on graphs, simplicial complexes, and metric spaces, reflecting information about their connectivity. The present paper aims to further understand the…

Combinatorics · Mathematics 2025-03-19 So Yamagata

Recently there has been growing interest in discrete homotopies and homotopies of graphs beyond treating graphs as 1-dimensional simplicial spaces. One such type of homotopy is $\times$-homotopy. Recent work by Chih-Scull has developed a…

Combinatorics · Mathematics 2025-04-22 Keira Behal , Tien Chih

We give the first tractable and systematic examples of nontrivial higher digraph homotopy groups. To do this we define relative digraph homotopy groups and show these satisfy a long exact sequence analogous to the relative homotopy groups…

Algebraic Topology · Mathematics 2025-04-08 Stephen Theriault , Jie Wu , Shing-Tung Yau , Mengmeng Zhang

The recently introduced A-homotopy groups for graphs are investigated. The main concern of the present article is the construction of an infinite cell complex, the homotopy groups of which are isomorphic to the A-homotopy groups of the…

Combinatorics · Mathematics 2007-05-23 E. Babson , H. Barcelo , M. de Longueville , R. Laubenbacher

We develop a generalisation of the path homology theory introduced by Grigor'yan, Lin, Muranov and Yau (GLMY-theory) in a general simplicial setting. The new theory includes as particular cases the GLMY-theory for path complexes and new…

Algebraic Topology · Mathematics 2024-02-21 Sergei O. Ivanov , Fedor Pavutnitskiy

The homotopy theory of gauge groups has received considerable attention in recent decades. In this work, we study the homotopy theory of gauge groups over some high dimensional manifolds. To be more specific, we study gauge groups of…

Algebraic Topology · Mathematics 2021-03-24 Ruizhi Huang

We develop a theory of $\times$-homotopy, fundamental groupoids and covering spaces that apply to non-simple graphs, generalizing existing results for simple graphs. We prove that $\times$-homotopies from finite graphs can be decomposed…

Combinatorics · Mathematics 2026-03-17 Tien Chih , Laura Scull

The notion of $\times$-homotopy from \cite{DocHom} is investigated in the context of the category of pointed graphs. The main result is a long exact sequence that relates the higher homotopy groups of the space $\Hom_*(G,H)$ with the…

Combinatorics · Mathematics 2008-07-07 Anton Dochtermann

In this text we expose basic cases of some fundamental ideas and methods of topology. Namely, of homotopy, degree, fundamental group, covering, Whitehead invariant, etc. This is done by considering the elementary example: closed polygonal…

History and Overview · Mathematics 2026-05-07 E. Alkin , O. Nikitenko , A. Skopenkov

We develop a theory of covering digraphs, similar to the theory of covering spaces. By applying this theory to Cayley digraphs, we build a "bridge" between GLMY-theory and group homology theory, which helps to reduce path homology…

Algebraic Topology · Mathematics 2024-04-02 Shaobo Di , Sergei O. Ivanov , Lev Mukoseev , Mengmeng Zhang

We describe various path homology theories constructed for a directed hypergraph. We introduce the category of directed hypergraphs and the notion of a homotopy in this category. Also, we investigate the functoriality and the homotopy…

Algebraic Topology · Mathematics 2021-09-22 Yuri Muranov , Anna Szczepkowska , Vladimir Vershinin

By introducing various topologies on the homotopy groups of a topological space, some researchers make these well known notions in algebraic topology more useful and powerful. In this paper, first we recall and review some known topologies…

Algebraic Topology · Mathematics 2026-02-25 Naghme Shahami , Behrooz Mashayekhy

We show that the category of graphs has the structure of a 2-category with homotopy as the 2-cells. We then develop an explicit description of homotopies for finite graphs, in terms of what we call `spider moves'. We then create a category…

Combinatorics · Mathematics 2020-05-15 Tien Chih , Laura Scull

We prove analogues of classical results for higher homotopy groups and singular homology groups of pseudotopological spaces. Pseudotopological spaces are a generalization of (\v{C}ech) closure spaces which are in turn a generalization of…

Algebraic Topology · Mathematics 2024-09-30 Nikola Milićević , Nicholas A. Scoville

We characterize the class of homotopy pull-back squares by means of elementary closure properties. The so called Puppe theorem which identifies the homotopy fiber of certain maps constructed as homotopy colimits is a straightforward…

Algebraic Topology · Mathematics 2007-05-23 W. Chacholski , W. Pitsch , J. Scherer

We study notions of persistent homotopy groups of compact metric spaces together with their stability properties in the Gromov-Hausdorff sense. We pay particular attention to the case of fundamental groups, for which we obtain a more…

Algebraic Topology · Mathematics 2022-09-13 Facundo Mémoli , Ling Zhou

Mirror graphs were introduced by Bre\v{s}ar et al. in 2004 as an intriguing class of graphs: vertex-transitive, isometrically embeddable into hypercubes, having a strong connection with regular maps and polytope structure. In this article…

Combinatorics · Mathematics 2016-09-05 Tilen Marc
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