{ "id": "1609.08885", "version": "v1", "published": "2016-09-28T12:33:18.000Z", "updated": "2016-09-28T12:33:18.000Z", "title": "On $g$-Extra Connectivity of Hypercube-like Networks", "authors": [ "Jin-Xin Zhou" ], "categories": [ "math.CO" ], "abstract": "Given a connected graph $G$ and a non-negative integer $g$, the {\\em $g$-extra connectivity} $\\k_g(G)$ of $G$ is the minimum cardinality of a set of vertices in $G$, if it exists, whose deletion disconnects $G$ and leaves each remaining component with more than $g$ vertices. This paper focuses on the $g$-extra connectivity of hypercube-like networks (HL-networks for short) which includes numerous well-known topologies, such as hypercubes, twisted cubes, crossed cubes and M\\\"obius cubes. All the known results suggest the equality $\\k_g(X_n)=f_n(g)$ holds, where $X_n$ is an $n$-dimensional HL-network, $f_n(g)=n(g+1)-\\frac{g(g+3)}{2}$, $n\\geq 5$ and $0\\leq g\\leq n-3$? Some authors also attempted to prove this equality in general. In this paper, we construct a subfamily of an $n$-dimensional HL-network with $g$-extra connectivity greater than $f_n(g)$ which implies that the above equality does not hold in general. We also prove that for $n\\geq 5$ and $0\\leq g\\leq n-3$, $\\k_g(X_n)\\geq f_n(g)$ always holds. This enables us to give a sufficient condition for the equality $\\k_g(X_n)=f_n(g)$, which is then used to determine the $g$-extra connectivity of HL-networks for some small $g$ or the $g$-extra connectivity of some particular subfamily of HL-networks. As a result, a short proof for the main results in [Journal of Computer and System Sciences 79 (2013) 669--688].", "revisions": [ { "version": "v1", "updated": "2016-09-28T12:33:18.000Z" } ], "analyses": { "keywords": [ "hypercube-like networks", "dimensional hl-network", "extra connectivity greater", "deletion disconnects", "paper focuses" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }