{ "id": "1602.03690", "version": "v1", "published": "2016-02-11T12:10:07.000Z", "updated": "2016-02-11T12:10:07.000Z", "title": "Constructing a weak subset of a random set", "authors": [ "Lu Liu" ], "comment": "10 pages", "categories": [ "math.LO" ], "abstract": "The tree forcing method given by (Liu 2015) enables the cone avoiding of strong enumeration of a given tree, within a subset or co-subset of an arbitrary given set, provided the given tree does not admit computable strong enumeration. Using this result, we settled and reproduced a series of problems in reverse mathematics. In this paper, we demonstrate cone avoiding results within an infinite subset of a given 1-random set. We show that for any given 1-random set $X$, there exists an infinite subset $Y$ of $X$ such that $Y$ does not compute any real with positive effective Hausdorff dimension, thus answering negatively a question posed by Kjos-Hanssen that whether there exists a 1-random set of which any infinite subset computes some 1-random real. The result is surprising in that the tree forcing technique used on the subset or co-subset seems to heavily rely on subset co-subset combinatorics, whereas this result does not.", "revisions": [ { "version": "v1", "updated": "2016-02-11T12:10:07.000Z" } ], "analyses": { "subjects": [ "68Q30" ], "keywords": [ "random set", "weak subset", "infinite subset", "admit computable strong enumeration", "demonstrate cone avoiding results" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160203690L" } } }