2010/11/29 by Vladimir Koltchinskii, Koltchinskii, Vladimir, Alexandre B. Tsybakov +3 · 649 citations
Engineering · Mathematics · #Advanced SAR Imaging Techniques #Applied mathematics #Combinatorics #Eigenvalues and eigenvectors #Estimator #Logarithm #Mathematical analysis #Mathematical optimization #Mathematics #Matrix (chemical analysis) #Matrix completion #Matrix norm #Minimax #Numerical methods in inverse problems #Rank (graph theory) #Rate of convergence #Sparse and Compressive Sensing Techniques #Statistics #Upper and lower bounds #math.ST #msc:60B20 #msc:60G15 #msc:62H12 #msc:62J99 #stat.ML #stat.TH
paper · pdf · doi:10.48550/arxiv.1011.6256
published in arXiv (Cornell University) (Cornell University)
arxiv created 2016/03/23 · arxiv updated 2016/03/24
This paper deals with the trace regression model where n entries or linear\ncombinations of entries of an unknown m1\× m2 matrix A0 corrupted by\nnoise are observed. We propose a new nuclear norm penalized estimator of A0\nand establish a general sharp oracle inequality for this estimator for\narbitrary values of n,m1,m2 under the condition of isometry in expectation.\nThen this method is applied to the matrix completion problem. In this case, the\nestimator admits a simple explicit form and we prove that it satisfies oracle\ninequalities with faster rates of convergence than in the previous works. They\nare valid, in particular, in the high-dimensional setting m1m2\≫ n. We\nshow that the obtained rates are optimal up to logarithmic factors in a minimax\nsense and also derive, for any fixed matrix A0, a non-minimax lower bound on\nthe rate of convergence of our estimator, which coincides with the upper bound\nup to a constant factor. Finally, we show that our procedure provides an exact\nrecovery of the rank of A0 with probability close to 1. We also discuss the\nstatistical learning setting where there is no underlying model determined by\nA0 and the aim is to find the best trace regression model approximating the\ndata.\n