English
Related papers

Related papers: Homotopy theory for digraphs

200 papers

Given a diagram of rings, one may consider the category of modules over them. We are interested in the homotopy theory of categories of this type: given a suitable diagram of model categories M(s) (as s runs through the diagram), we…

Algebraic Topology · Mathematics 2013-09-27 J. P. C. Greenlees , B. Shipley

\"Uberhomology is a recently defined homology theory for simplicial complexes, which yields subtle information on graphs. We prove that bold homology, a certain specialisation of \"uberhomology, is related to dominating sets in graphs. To…

Algebraic Topology · Mathematics 2023-08-17 Luigi Caputi , Daniele Celoria , Carlo Collari

We combine Homotopy Type Theory with axiomatic cohesion, expressing the latter internally with a version of "adjoint logic" in which the discretization and codiscretization modalities are characterized using a judgmental formalism of "crisp…

Category Theory · Mathematics 2017-04-26 Michael Shulman

Motivated by constructions in topological data analysis and algebraic combinatorics, we study homotopy theory on the category of Cech closure spaces $\mathbf{Cl}$, the category whose objects are sets endowed with a Cech closure operator and…

Algebraic Topology · Mathematics 2022-09-28 Antonio Rieser

We extend the theory of probability graphons, continuum representations of edge-decorated graphs arising in graph limits theory, to the 'right convergence' point of view. First of all, we generalise the notions of overlay functionals and…

Probability · Mathematics 2024-07-09 Giulio Zucal

Two graphs $G$ and $H$ are homomorphism indistinguishable over a class of graphs $\mathcal{F}$ if for all graphs $F \in \mathcal{F}$ the number of homomorphisms from $F$ to $G$ is equal to the number of homomorphisms from $F$ to $H$. Many…

Combinatorics · Mathematics 2024-02-07 Tim Seppelt

The complexity of graph homomorphism problems has been the subject of intense study. It is a long standing open problem to give a (decidable) complexity dichotomy theorem for the partition function of directed graph homomorphisms. In this…

Computational Complexity · Computer Science 2010-08-06 Jin-Yi Cai , Xi Chen

We introduce a notion of graph homeomorphisms which uses the concept of dimension and homotopy for graphs. It preserves the dimension of a subbasis, cohomology and Euler characteristic. Connectivity and homotopy look as in classical…

General Topology · Mathematics 2014-01-14 Oliver Knill

For real application and theoretical investigation of ordinary hypergraphs and non-ordinary hypergraphs, researchers need to establish standard rules and feasible operating methods. We propose a visualization tool for investigating…

History and Overview · Mathematics 2025-03-27 Fei Ma , Bing Yao

The Fundamental Morphism Theorem is a categorical version of the First Noether Isomorphism Theorem for categories that do not have kernels or cokernels. We consider two categories of graphs. Both categories will admit graphs with multiple…

Combinatorics · Mathematics 2018-08-31 Tien Chih , Demitri Plessas

A multipath in a directed graph is a disjoint union of paths. The multipath complex of a directed graph ${\tt G}$ is the simplicial complex whose faces are the multipaths of ${\tt G}$. We compute the Euler characteristic, and associated…

Combinatorics · Mathematics 2022-08-10 Luigi Caputi , Carlo Collari , Sabino Di Trani , Jason P. Smith

By considering homotopies that preserve the stratification, one obtains a natural notion of homotopy for stratified spaces. In this short note, we introduce invariants of stratified homotopy, the stratified homotopy groups. We show that…

Algebraic Topology · Mathematics 2019-04-04 Sylvain Douteau

We give rigorous foundations for parametrized homotopy theory in this monograph. After preliminaries on point-set topology, base change functors, and proper actions of non-compact Lie groups, we develop the homotopy theory of equivariant…

Algebraic Topology · Mathematics 2007-05-23 J. P. May , J. Sigurdsson

We unify several seemingly different graph and digraph classes under one umbrella. These classes are all broadly speaking different generalizations of interval graphs, and include, in addition to interval graphs, also adjusted interval…

Discrete Mathematics · Computer Science 2018-06-28 Pavol Hell , Jing Huang , Ross M. McConnell , Arash Rafiey

We study the rational homotopy types of classifying spaces of automorphism groups of smooth simply connected manifolds of dimension at least five. We give dg Lie algebra models for the homotopy automorphisms and the block diffeomorphisms of…

Algebraic Topology · Mathematics 2020-01-16 Alexander Berglund , Ib Madsen

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

Graph homomorphism has been an important research topic since its introduction [17]. Stated in the language of binary relational structures in that paper [17], Lov\'asz proved a fundamental theorem that, for a graph $H$ given by its $0$-$1$…

Discrete Mathematics · Computer Science 2021-02-25 Jin-Yi Cai , Artem Govorov

This is partly a survey and partly a research article. Some known results and open problems about Kaehler groups (fundamental groups of compact Kaehler manifolds) are discussed. A new notion of Kaehler homomorphism is introduced. This is a…

Algebraic Geometry · Mathematics 2009-08-07 Donu Arapura

In order to make the fundamental group, one of the most well known invariants in algebraic topology, more useful and powerful some researchers have introduced and studied various topologies on the fundamental group from the beginning of the…

Algebraic Topology · Mathematics 2025-08-28 Naghme Shahami , Behrooz Mashayekhy

We examine bicoset digraphs and their natural properties from the point of view of symmetry. We then consider connected bicoset digraphs that are $X$-joins with collections of empty graphs, and show that their automorphism groups can be…

Combinatorics · Mathematics 2024-09-18 Rachel Barber , Ted Dobson , Gregory Robson