Campus Units

Mathematics, Computer Science

Document Type

Article

Publication Version

Submitted Manuscript

Publication Date

5-2015

Journal or Book Title

Mathematical Logic Quarterly

Volume

61

Issue

3

First Page

189

Last Page

195

DOI

10.1002/malq.201300081

Abstract

We classify the asymptotic densities of the Delta(0)(2) sets according to their level in the Ershov hierarchy. In particular, it is shown that for n2, a real r[0,1] is the density of an n-c.e. set if and only if it is a difference of left-Delta(0)(2) reals. Further, we show that the densities of the w-c.e. sets coincide with the densities of the Delta(0)(2) sets, and there are n-c.e. sets whose density is not the density of an n-c.e. set for any n epsilon omega.

Comments

This is the pre-peer reviewed version of the following article: Downey, Rod, Carl Jockusch, Timothy H. McNicholl, and Paul Schupp. "Asymptotic density and the Ershov hierarchy." Mathematical Logic Quarterly 61, no. 3 (2015): 189-195, which has been published in final form at doi:10.1002/malq.201300081. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving. Posted with permission.

Copyright Owner

Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Language

en

File Format

application/pdf

Published Version

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