{ "id": "2204.10681", "version": "v1", "published": "2022-04-22T12:53:29.000Z", "updated": "2022-04-22T12:53:29.000Z", "title": "A Weak Law of Large Numbers for Dependent Random Variables", "authors": [ "Ioannis Karatzas", "Walter Schachermayer" ], "categories": [ "math.PR" ], "abstract": "Every sequence $f_1, f_2, \\cdots \\, $ of random variables with $ \\, \\lim_{M \\to \\infty} \\big( M \\sup_{k \\in \\mathbb{N}} \\mathbb{P} ( |f_k| > M ) \\big)=0\\,$ contains a subsequence $ f_{k_1}, f_{k_2} , \\cdots \\,$ that satisfies, along with all its subsequences, the weak law of large numbers: $ \\, \\lim_{N \\to \\infty} \\big( (1/N) \\sum_{n=1}^N f_{k_n} - D_N \\big) =0\\,,$ in probability. Here $\\, D_N\\, $ is a \"corrector\" random variable with values in $[-N,N]$, for each $N \\in \\mathbb{N} $; these correctors are all equal to zero if, in addition, $\\, \\liminf_{k \\to \\infty} \\mathbb{E} \\big( f_k^2 \\, \\mathbf{ 1}_{ \\{ |f_k| \\le M \\} } \\big) =0\\,$ holds for every $M \\in (0, \\infty)\\,.$", "revisions": [ { "version": "v1", "updated": "2022-04-22T12:53:29.000Z" } ], "analyses": { "subjects": [ "60A10", "60F15" ], "keywords": [ "dependent random variables", "large numbers", "weak law", "subsequence", "probability" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }