{ "id": "1805.00535", "version": "v1", "published": "2018-05-01T20:05:41.000Z", "updated": "2018-05-01T20:05:41.000Z", "title": "Hamiltonicity of $2$-block intersection graphs of ${\\rm{TS}}(v,λ)$: $v\\equiv 0$ or $4\\pmod{12}$", "authors": [ "John Asplund", "Melissa Keranen" ], "comment": "19 pages, 23 figures", "categories": [ "math.CO" ], "abstract": "A ${\\rm{TS}}(v,\\lambda)$ is a pair $(V,\\mathcal{B})$ where $V$ contains $v$ points and $\\mathcal{B}$ contains $3$-element subsets of $V$ so that each pair in $V$ appears in exactly $\\lambda$ blocks. A $2$-block intersection graph ($2$-BIG) of a ${\\rm{TS}}(v,\\lambda)$ is a graph where each vertex is represented by a block from the ${\\rm{TS}}(v,\\lambda)$ and each pair of blocks $B_i,B_j\\in \\mathcal{B}$ are joined by an edge if $|B_i\\cap B_j|=2$. Using constructions for ${\\rm{TS}}(v,\\lambda)$ given by Schreiber, we show that there exists a ${\\rm{TS}}(v,\\lambda)$ for $v\\equiv 0$ or $4\\pmod{12}$ whose $2$-BIG is Hamiltonian.", "revisions": [ { "version": "v1", "updated": "2018-05-01T20:05:41.000Z" } ], "analyses": { "subjects": [ "05C45", "05C51" ], "keywords": [ "block intersection graph", "hamiltonicity", "element subsets", "hamiltonian" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }