{ "id": "1601.07158", "version": "v1", "published": "2016-01-26T20:38:39.000Z", "updated": "2016-01-26T20:38:39.000Z", "title": "As Easy as $\\mathbb Q$: Hilbert's Tenth Problem for Subrings of the Rationals and Number Fields", "authors": [ "Kirsten Eisentraeger", "Russell Miller", "Jennifer Park", "Alexandra Shlapentokh" ], "categories": [ "math.NT", "math.LO" ], "abstract": "Hilbert's Tenth Problem over the field $\\mathbb Q$ of rational numbers is one of the biggest open problems in the area of undecidability in number theory. In this paper we construct new, computably presentable subrings $R$ of $\\mathbb Q$ having the property that Hilbert's Tenth Problem for $R$, denoted $HTP(R)$, is Turing equivalent to $HTP(\\mathbb Q)$. We are able to put several additional constraints on the rings $R$ that we construct. Given any computable nonnegative real number $r \\leq 1$ we construct such a ring $R = Z[\\frac1p : p \\in S]$ with $S$ a set of primes of lower density $r$. We also construct examples of rings $R$ for which deciding membership in $R$ is Turing equivalent to deciding $HTP(R)$ and also equivalent to deciding $HTP(\\mathbb Q)$. Alternatively, we can make $HTP(R)$ have arbitrary computably enumerable degree above $HTP(\\mathbb Q)$. Finally, we show that the same can be done for subrings of number fields and their prime ideals.", "revisions": [ { "version": "v1", "updated": "2016-01-26T20:38:39.000Z" } ], "analyses": { "subjects": [ "11U05", "12L05", "03D45" ], "keywords": [ "number fields", "biggest open problems", "turing equivalent", "arbitrary computably enumerable degree", "construct examples" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }