{ "id": "1501.06521", "version": "v1", "published": "2015-01-26T18:48:55.000Z", "updated": "2015-01-26T18:48:55.000Z", "title": "Tensor Prediction, Rademacher Complexity and Random 3-XOR", "authors": [ "Boaz Barak", "Ankur Moitra" ], "comment": "20 pages", "categories": [ "cs.LG", "cs.DS", "stat.ML" ], "abstract": "Here we study the tensor prediction problem, where the goal is to accurately predict the entries of a low rank, third-order tensor (with noise) given as few observations as possible. We give algorithms based on the sixth level of the sum-of-squares hierarchy that work with $m = \\tilde{O}(n^{3/2})$ observations, and we complement our result by showing that any attempt to solve tensor prediction with $m = O(n^{3/2 - \\epsilon})$ observations through the sum-of-squares hierarchy needs $\\Omega(n^{2 \\epsilon})$ rounds and consequently would run in moderately exponential time. In contrast, information theoretically $m = \\tilde{O}(n)$ observations suffice. Our approach is to characterize the Rademacher complexity of the sequence of norms that arise from the sum-of-squares hierarchy, and both our upper and lower bounds are based on establishing connections between tensor prediction and the task of strongly refuting random $3$-XOR formulas, and the resolution proof system.", "revisions": [ { "version": "v1", "updated": "2015-01-26T18:48:55.000Z" } ], "analyses": { "keywords": [ "rademacher complexity", "sum-of-squares hierarchy needs", "tensor prediction problem", "resolution proof system", "observations suffice" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150106521B" } } }