{ "id": "2106.13345", "version": "v1", "published": "2021-06-24T22:58:51.000Z", "updated": "2021-06-24T22:58:51.000Z", "title": "The Hanson-Wright Inequality for Random Tensors", "authors": [ "Stefan Bamberger", "Felix Krahmer", "Rachel Ward" ], "categories": [ "math.PR" ], "abstract": "We provide moment bounds for expressions of the type $(X^{(1)} \\otimes \\dots \\otimes X^{(d)})^T A (X^{(1)} \\otimes \\dots \\otimes X^{(d)})$ where $\\otimes$ denotes the Kronecker product and $X^{(1)}, \\dots, X^{(d)}$ are random vectors with independent, mean 0, variance 1, subgaussian entries. The bounds are tight up to constants depending on $d$ for the case of Gaussian random vectors. Our proof also provides a decoupling inequality for expressions of this type. Using these bounds, we obtain new, improved concentration inequalities for expressions of the form $\\|B (X^{(1)} \\otimes \\dots \\otimes X^{(d)})\\|_2$.", "revisions": [ { "version": "v1", "updated": "2021-06-24T22:58:51.000Z" } ], "analyses": { "keywords": [ "random tensors", "hanson-wright inequality", "expressions", "gaussian random vectors", "moment bounds" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }