{ "id": "1903.12325", "version": "v1", "published": "2019-03-29T02:22:48.000Z", "updated": "2019-03-29T02:22:48.000Z", "title": "Entropy flow and De Bruijn's identity for a class of stochastic differential equations driven by fractional Brownian motion", "authors": [ "Michael C. H. Choi", "Chihoon Lee", "Jian Song" ], "comment": "10 pages", "categories": [ "math.PR", "cs.IT", "math.IT" ], "abstract": "Motivated by the classical De Bruijn's identity for the additive Gaussian noise channel, in this paper we consider a generalized setting where the channel is modelled via stochastic differential equations driven by fractional Brownian motion with Hurst parameter $H\\in(1/4,1)$. We derive generalized De Bruijn's identity for Shannon entropy and Kullback-Leibler divergence by means of It\\^o's formula, and present two applications where we relax the assumption to $H \\in (0,1)$. In the first application we demonstrate its equivalence with Stein's identity for Gaussian distributions, while in the second application, we show that for $H \\in (0,1/2]$, the entropy power is concave in time while for $H \\in (1/2,1)$ it is convex in time when the initial distribution is Gaussian. Compared with the classical case of $H = 1/2$, the time parameter plays an interesting and significant role in the analysis of these quantities.", "revisions": [ { "version": "v1", "updated": "2019-03-29T02:22:48.000Z" } ], "analyses": { "subjects": [ "60G22", "60G15" ], "keywords": [ "stochastic differential equations driven", "fractional brownian motion", "bruijns identity", "entropy flow", "gaussian noise channel" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }