{ "id": "1503.06473", "version": "v1", "published": "2015-03-22T20:31:54.000Z", "updated": "2015-03-22T20:31:54.000Z", "title": "Local spectral gap in simple Lie groups and applications", "authors": [ "Rémi Boutonnet", "Adrian Ioana", "Alireza Salehi Golsefidy" ], "categories": [ "math.GR", "math.CO", "math.DS" ], "abstract": "We introduce a novel notion of {\\it local spectral gap} for general, possibly infinite, measure preserving actions. We establish local spectral gap for the left translation action $\\Gamma\\curvearrowright G$, whenever $\\Gamma$ is a dense subgroup generated by algebraic elements of an arbitrary connected simple Lie group $G$. This extends to the non-compact setting recent works of Bourgain and Gamburd \\cite{BG06,BG10}, and Benoist and de Saxc\\'{e} \\cite{BdS14}. We present several applications to the Banach-Ruziewicz problem, orbit equivalence rigidity, continuous and monotone expanders, and bounded random walks on $G$. In particular, we prove that, up to a multiplicative constant, the Haar measure is the unique $\\Gamma$-invariant finitely additive measure defined on all bounded measurable subsets of $G$.", "revisions": [ { "version": "v1", "updated": "2015-03-22T20:31:54.000Z" } ], "analyses": { "keywords": [ "applications", "arbitrary connected simple lie group", "finitely additive measure", "left translation action", "establish local spectral gap" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150306473B" } } }