{ "id": "2003.09144", "version": "v1", "published": "2020-03-20T08:30:58.000Z", "updated": "2020-03-20T08:30:58.000Z", "title": "Closures of Union-Closed Families", "authors": [ "Dhruv Bhasin" ], "categories": [ "math.CO" ], "abstract": "Given a Union-Closed family, which is not equal to the power set of its universe, say $[n]$, one can always add a new set $A\\subsetneq[n]$ to it, such that the new family remains Union-Closed. We construct a new family by collecting all such $A$'s and call this family the closure of $\\mathcal F$. We study various properties of this closure. We characterize families whose closure becomes the power set of $[n]$ and give a checking criteria of closure roots of such families, i.e., existence of $\\mathcal H$ such that closure of $\\mathcal H=\\mathcal F$.", "revisions": [ { "version": "v1", "updated": "2020-03-20T08:30:58.000Z" } ], "analyses": { "keywords": [ "union-closed family", "power set", "closure roots", "family remains" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }