Saved in:
Bibliographic Details
Main Author: Matsushita, Takahiro
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2412.19144
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910009172951040
author Matsushita, Takahiro
author_facet Matsushita, Takahiro
contents The Hom complex $\mathrm{Hom}(G, H)$ of graphs is a simplicial complex associated to a pair of graphs $G$ and $H$, and its homotopy type is of interest in the graph coloring problem and the homomorphism reconfiguration problem. In this paper, we show that if $G$ is a connected graph and $H$ is a square-free connected graph, then every connected component of $\mathrm{Hom}(G, H)$ is homotopy equivalent to a point, a circle, $H$ or a connected double cover over $H$. We also obtain a certain relation between the fundamental group of $\mathrm{Hom}(G,H)$ and realizable walks studied in the homomorphism reconfiguration problem.
format Preprint
id arxiv_https___arxiv_org_abs_2412_19144
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Hom complexes of graphs whose codomains are square-free
Matsushita, Takahiro
Combinatorics
Algebraic Topology
The Hom complex $\mathrm{Hom}(G, H)$ of graphs is a simplicial complex associated to a pair of graphs $G$ and $H$, and its homotopy type is of interest in the graph coloring problem and the homomorphism reconfiguration problem. In this paper, we show that if $G$ is a connected graph and $H$ is a square-free connected graph, then every connected component of $\mathrm{Hom}(G, H)$ is homotopy equivalent to a point, a circle, $H$ or a connected double cover over $H$. We also obtain a certain relation between the fundamental group of $\mathrm{Hom}(G,H)$ and realizable walks studied in the homomorphism reconfiguration problem.
title Hom complexes of graphs whose codomains are square-free
topic Combinatorics
Algebraic Topology
url https://arxiv.org/abs/2412.19144