{ "id": "2001.06775", "version": "v1", "published": "2020-01-19T05:01:00.000Z", "updated": "2020-01-19T05:01:00.000Z", "title": "Distance $r$-domination number and $r$-independence complexes of graphs", "authors": [ "Priyavrat Deshpande", "Samir Shukla", "Anurag Singh" ], "comment": "14 pages", "categories": [ "math.CO", "math.AT" ], "abstract": "For $r\\geq 1$, the $r$-independence complex of a graph $G$, denoted Ind$_r(G)$, is a simplicial complex whose faces are subsets $A \\subseteq V(G)$ such that each component of the induced subgraph $G[A]$ has at most $r$ vertices. In this article, we establish a relation between the distance $r$-domination number of $G$ and (homological) connectivity of Ind$_r(G)$. We also prove that Ind$_r(G)$, for a chordal graph $G$, is either contractible or homotopy equivalent to a wedge of spheres. Given a wedge of spheres, we also provide a construction of a chordal graph whose $r$-independence complex has the homotopy type of the given wedge.", "revisions": [ { "version": "v1", "updated": "2020-01-19T05:01:00.000Z" } ], "analyses": { "subjects": [ "05C69", "55P15" ], "keywords": [ "independence complex", "domination number", "chordal graph", "homotopy type", "homotopy equivalent" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }