Title
Amplification and Derandomization without Slowdown.
Abstract
We present techniques for decreasing the error probability of randomized algorithms and for converting randomized algorithms to deterministic (nonuniform) algorithms. Unlike most existing techniques that involve repetition of the randomized algorithm and hence a slowdown, our techniques produce algorithms with similar run-time to the original randomized algorithms. The amplification technique applies when there is a quick, probabilistic test of the randomness. In this case, we show how to efficiently find one randomness string for the algorithm that works with very high probability and apply the algorithm only on that randomness (in contrast, standard approaches suggest a number of possible randomness strings and run the algorithm on all of them). The search of good randomness turns out to be a natural stochastic multiarmed bandit problem, which we define ("the biased coin problem") and analyze. The derandomization technique applies when there is a verifier that can test the randomness of the algorithm while only inspecting a sublinear size sketch of the input (the sketch may be hard to compute; the verifier may be inefficient and is allowed to reject a small portion of the good randomness strings). In this case, we show how to apply Adleman's derandomization (from the proof of BPP subset of P/poly) more efficiently. We demonstrate the techniques by showing applications for dense max-cut, approximate clique, free games, and going from list decoding to unique decoding for Reed-Muller codes.
Year
DOI
Venue
2020
10.1137/17M1110596
SIAM JOURNAL ON COMPUTING
Keywords
DocType
Volume
derandomization,amplification,sketching
Journal
49
Issue
ISSN
Citations 
5
0097-5397
0
PageRank 
References 
Authors
0.34
0
2
Name
Order
Citations
PageRank
Ofer Grossman1104.70
Dana Moshkovitz236819.14