Dadush, Daniel, Guzmán, Cristóbal and Olver, Neil
(2018)
*Fast, deterministic and sparse dimensionality reduction.*
In: ACM SIAM Symposium on Discrete Algorithms, 2018-01-07 - 2018-01-10, University of Warwick, UK.

## Abstract

We provide a deterministic construction of the sparse JohnsonLindenstrauss transform of Kane & Nelson (J.ACM 2014) which runs, under a mild restriction, in the time necessary to apply the sparse embedding matrix to the input vectors. Specifically, given a set of n vectors in R d and target error ε, we give a deterministic algorithm to compute a {−1, 0, 1} embedding matrix of rank O((ln n)/ε2 ) with O((ln n)/ε) entries per column which preserves the norms of the vectors to within 1±ε. If NNZ, the number of non-zero entries in the input set of vectors, is Ω(d 2 ), our algorithm runs in time O(NNZ · ln n/ε). One ingredient in our construction is an extremely simple proof of the Hanson-Wright inequality for subgaussian random variables, which is more amenable to derandomization. As an interesting byproduct, we are able to derive the essentially optimal form of the inequality in terms of its functional dependence on the parameters.

Item Type: | Conference or Workshop Item (Paper) |
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Official URL: | https://archive.siam.org/meetings/da18/ |

Additional Information: | © 2018 by SIAM |

Divisions: | Mathematics |

Subjects: | Q Science > QA Mathematics |

Date Deposited: | 23 Jan 2020 16:48 |

Last Modified: | 20 Jun 2020 01:39 |

URI: | http://eprints.lse.ac.uk/id/eprint/103166 |

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