{ "id": "1711.01222", "version": "v1", "published": "2017-11-03T16:12:04.000Z", "updated": "2017-11-03T16:12:04.000Z", "title": "Rigidity at infinity for lattices in rank-one Lie groups", "authors": [ "Alessio Savini" ], "comment": "18 pages", "categories": [ "math.GT", "math.DG" ], "abstract": "Let $\\Gamma$ be a non-uniform lattice in $PU(p,1)$ without torsion and with $p\\geq2 $. We introduce the notion of volume for a representation $\\rho:\\Gamma \\rightarrow PU(m,1)$ where $m \\geq p$. We use this notion to generalize the Mostow--Prasad rigidity theorem. More precisely, we show that given a sequence of representations $\\rho_n:\\Gamma \\rightarrow PU(m,1)$ such that $\\lim_{n \\to \\infty} \\text{Vol}(\\rho_n) =\\text{Vol}(M)$, then there must exist a sequence of elements $g_n \\in PU(m,1)$ such that the representations $g_n \\circ \\rho_n \\circ g_n^{-1}$ converge to a reducible representation $\\rho_\\infty$ which preserves a totally geodesic copy of $\\mathbb{H}^p_\\mathbb{C}$ and whose $\\mathbb{H}^p_\\mathbb{C}$-component is conjugated to the standard lattice embedding $i:\\Gamma \\rightarrow PU(p,1) < PU(m,1)$. Additionally, we show that the same definitions and results can be adapted when $\\Gamma$ is a non-uniform lattice of $PSp(p,1)$ without torsion and for representations $\\rho:\\Gamma \\rightarrow PSp(m,1)$, still mantaining the hypothesis $m \\geq p \\geq 2$.", "revisions": [ { "version": "v1", "updated": "2017-11-03T16:12:04.000Z" } ], "analyses": { "subjects": [ "53C24", "53C35", "22E40" ], "keywords": [ "rank-one lie groups", "non-uniform lattice", "mostow-prasad rigidity theorem", "standard lattice", "totally geodesic copy" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }