{ "id": "1608.03863", "version": "v1", "published": "2016-08-12T18:08:06.000Z", "updated": "2016-08-12T18:08:06.000Z", "title": "Large deviations for random projections of $\\ell_p^n$-balls -- the complete picture", "authors": [ "David Alonso-GutiƩrrez", "Joscha Prochno", "Christoph Thaele" ], "categories": [ "math.PR", "math.FA" ], "abstract": "The paper provides a complete description of the large deviation behavior for the Euclidean norm of projections of $\\ell_p^n$-balls to random subspaces of any dimension. More precisely, for each integer $n\\geq 1$, let $k_n\\in\\{1,\\ldots,n-1\\}$, $E^{(n)}$ be a uniform random $k_n$-dimensional subspace of $\\mathbb R^n$ and $X^{(n)}$ be a random point that is uniformly distributed in the $\\ell_p^n$-ball of $\\mathbb R^n$ for some $p\\in[1,\\infty]$. Then the Euclidean norms $\\|P_{E^{(n)}}X^{(n)}\\|_2$ of the orthogonal projections are shown to satisfy a large deviation principle (LDP), as the space dimension $n$ tends to infinity. Its speed and rate function are identified, making thereby visible how they depend on $p$ and the growth of the sequence of subspace dimensions $k_n$.", "revisions": [ { "version": "v1", "updated": "2016-08-12T18:08:06.000Z" } ], "analyses": { "subjects": [ "60F10", "52A23", "60D05", "46B09" ], "keywords": [ "complete picture", "random projections", "euclidean norm", "large deviation principle", "large deviation behavior" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }