{ "id": "1710.00505", "version": "v1", "published": "2017-10-02T06:45:21.000Z", "updated": "2017-10-02T06:45:21.000Z", "title": "Hamiltonicity in random graphs is born resilient", "authors": [ "Richard Montgomery" ], "comment": "18 pages, submitted", "categories": [ "math.CO" ], "abstract": "Let $\\{G_M\\}_{M\\geq 0}$ be the random graph process, where $G_0$ is the empty graph on $n$ vertices and subsequent graphs in the sequence are obtained by adding a new edge uniformly at random. For each $\\varepsilon>0$, we show that, almost surely, any graph $G_M$ with minimum degree at least 2 is not only Hamiltonian (as shown by Bollob\\'as), but remains Hamiltonian despite the removal of any set of edges, as long as at most $(1/2-\\varepsilon)$ of the edges incident to each vertex are removed. We say that such a graph is $(1/2-\\varepsilon)$-resiliently Hamiltonian. Furthermore, for each $\\epsilon>0$, we show that, almost surely, each graph $G_M$ is not $(1/2+\\varepsilon)$-resiliently Hamiltonian. These results strengthen those by Lee and Sudakov on the likely resilience of Hamiltonicity in the binomial random graph. For each $k$, we denote by $G^{(k)}$ the (possibly empty) maximal subgraph with minimum degree at least $k$ of a graph $G$. That is, the $k$-core of $G$. Krivelevich, Lubetzky and Sudakov have shown that, for each $k\\geq 15$, in almost every random graph process $\\{G_M\\}_{M\\geq 0}$, every non-empty $k$-core is Hamiltonian. We show that, for each $\\varepsilon>0$ and $k\\geq k_0(\\varepsilon)$, in almost every random graph process $\\{G_M\\}_{M\\geq 0}$, every non-empty $k$-core is $(1/2-\\varepsilon)$-resiliently Hamiltonian, but not $(1/2+\\varepsilon)$-resiliently Hamiltonian.", "revisions": [ { "version": "v1", "updated": "2017-10-02T06:45:21.000Z" } ], "analyses": { "keywords": [ "random graph process", "born resilient", "resiliently hamiltonian", "hamiltonicity", "minimum degree" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }