{ "id": "1612.03837", "version": "v1", "published": "2016-12-12T18:37:10.000Z", "updated": "2016-12-12T18:37:10.000Z", "title": "On H-Spaces and a Congruence of Catalan Numbers", "authors": [ "Tamar Friedmann", "John R. Harper" ], "comment": "15 pages; accepted for publication in Homology, Homotopy and Applications", "categories": [ "math.CO", "math.AT", "math.NT" ], "abstract": "For $p$ an odd prime and $F$ the cyclic group of order $p$, we show that the number of conjugacy classes of embeddings of $F$ in $SU(p)$ such that no element of $F$ has 1 as an eigenvalue is $(1+C_{p-1})/p$, where $C_{p-1}$ is a Catalan number. We prove that the only coset space $SU(p)/F$ that admits a $p$-local $H$-structure is the classical Lie group $PSU(p)$. We also show that $SU(4)/\\mathbb Z_3$, where $\\mathbb Z_3$ is embedded off the center of $SU(4)$, is a novel example of an $H$-space, even globally. We apply our results to the study of homotopy classes of maps from $BF$ to $BSU(n)$.", "revisions": [ { "version": "v1", "updated": "2016-12-12T18:37:10.000Z" } ], "analyses": { "subjects": [ "05A15", "55P45", "05E15", "11A07", "11B50" ], "keywords": [ "catalan number", "congruence", "coset space", "cyclic group", "odd prime" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }