Abstract | ||
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This is the second part of a two-paper series on generalized inverses that minimize matrix norms. In Part II we focus on generalized inverses that are minimizers of entrywise p norms whose main representative is the sparse pseudoinverse for $p = 1$. We are motivated by the idea to replace the Moore-Penrose pseudoinverse by a sparser generalized inverse which is in some sense well-behaved. Sparsity implies that it is faster to apply the resulting matrix; well-behavedness would imply that we do not lose much in stability with respect to the least-squares performance of the MPP. We first address questions of uniqueness and non-zero count of (putative) sparse pseu-doinverses. We show that a sparse pseudoinverse is generically unique, and that it indeed reaches optimal sparsity for almost all matrices. We then turn to proving our main stability result: finite-size concentration bounds for the Frobenius norm of p-minimal inverses for $1 ≤ p ≤ 2$. Our proof is based on tools from convex analysis and random matrix theory, in particular the recently developed convex Gaussian min-max theorem. Along the way we prove several results about sparse representations and convex programming that were known folklore, but of which we could find no proof. |
Year | Venue | Field |
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2017 | arXiv: Information Theory | Uniqueness,Discrete mathematics,Combinatorics,Mathematical optimization,Matrix (mathematics),Moore–Penrose pseudoinverse,Generalized inverse,Matrix norm,Block matrix pseudoinverse,Convex optimization,Convex analysis,Mathematics |
DocType | Volume | Citations |
Journal | abs/1706.08701 | 0 |
PageRank | References | Authors |
0.34 | 8 | 2 |
Name | Order | Citations | PageRank |
---|---|---|---|
Ivan Dokmanic | 1 | 155 | 22.37 |
Rémi Gribonval | 2 | 1207 | 83.59 |