{ "id": "1303.3595", "version": "v2", "published": "2013-03-14T20:36:40.000Z", "updated": "2013-04-01T20:28:22.000Z", "title": "Sparse approximation and recovery by greedy algorithms", "authors": [ "Eugene Livshitz", "Vladimir Temlyakov" ], "categories": [ "math.NA" ], "abstract": "We study sparse approximation by greedy algorithms. Our contribution is two-fold. First, we prove exact recovery with high probability of random $K$-sparse signals within $\\lceil K(1+\\e)\\rceil$ iterations of the Orthogonal Matching Pursuit (OMP). This result shows that in a probabilistic sense the OMP is almost optimal for exact recovery. Second, we prove the Lebesgue-type inequalities for the Weak Chebyshev Greedy Algorithm, a generalization of the Weak Orthogonal Matching Pursuit to the case of a Banach space. The main novelty of these results is a Banach space setting instead of a Hilbert space setting. However, even in the case of a Hilbert space our results add some new elements to known results on the Lebesque-type inequalities for the RIP dictionaries. Our technique is a development of the recent technique created by Zhang.", "revisions": [ { "version": "v2", "updated": "2013-04-01T20:28:22.000Z" } ], "analyses": { "subjects": [ "41A65", "41A25", "41A46", "46B20" ], "keywords": [ "exact recovery", "weak chebyshev greedy algorithm", "hilbert space", "weak orthogonal matching pursuit", "study sparse approximation" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1303.3595L" } } }