{ "id": "2005.02915", "version": "v1", "published": "2020-05-06T15:45:41.000Z", "updated": "2020-05-06T15:45:41.000Z", "title": "An almost sure invariance principle for some classes of inhomogeneous Markov chains and non-stationary $ρ$-mixing sequences", "authors": [ "Yeor Hafouta" ], "comment": "14 pp", "categories": [ "math.PR" ], "abstract": "We prove a vector-valued almost sure invariance principle for partial sums generated by uniformly contracting or elliptic Markov chains and a uniformly bounded sequence of functions. In the real-valued case we will also consider other types of non-stationary $\\rho$-mixing sequences. In the scalar case, when the variance $\\sig_n^2$ of the underlying partial sums $S_n$ grows at least as fast as $n^\\ve$ (for some $\\ve>0$), we obtain the rate $\\sig_n^{1/2+\\del}$ for any $\\del>0$, while in the vector-valued case, for sufficiently regular functions, we obtain the rate $s_n^{1/2+\\del}$, where $s_n^2=\\min_{|v|=1}v\\cdot \\text{Cov}(S_n)v$ is the \"growth rate\" of the of covariance matrix of $S_n$ in the space of positive definite matrices.", "revisions": [ { "version": "v1", "updated": "2020-05-06T15:45:41.000Z" } ], "analyses": { "keywords": [ "sure invariance principle", "inhomogeneous markov chains", "mixing sequences", "non-stationary", "partial sums" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }