{ "id": "2303.09488", "version": "v1", "published": "2023-03-16T17:07:47.000Z", "updated": "2023-03-16T17:07:47.000Z", "title": "Regularity of laws via Dirichlet forms -- Application to quadratic forms in independent and identically distributed random variables", "authors": [ "Ronan Herry", "Dominique Malicet", "Guillaume Poly" ], "comment": "33 pages, comments are welcome", "categories": [ "math.PR", "math.FA" ], "abstract": "We present a new tool to study the regularity of a function $F$ of a sequence $(X_{i})$ of independent and identically distributed random variables. Our main result states that, under mild conditions on the law of $X_{1}$, the regularity of the law of $F$ is controlled by the regularity of the law of a conditionally Gaussian object, canonically associated with $F$. At the technical level our analysis relies on the formalism of Dirichlet forms and an explicit construction of the Malliavin derivative of $F$ in the direction of a Gaussian space. As an application, we derive an explicit control of the regularity of the law of a quadratic from in the $X_{i}$'s in terms of spectral quantities, when the law of $X_{1}$ belongs to a large class of distribution including, for instance, all the Gaussian, all the Beta, all the Gamma, and all the polynomials thereof.", "revisions": [ { "version": "v1", "updated": "2023-03-16T17:07:47.000Z" } ], "analyses": { "subjects": [ "60H07", "31C25", "60E05" ], "keywords": [ "identically distributed random variables", "dirichlet forms", "regularity", "quadratic forms", "independent" ], "note": { "typesetting": "TeX", "pages": 33, "language": "en", "license": "arXiv", "status": "editable" } } }