Coherent randomness tests and computing the K-trivial sets

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10325909" target="_blank" >RIV/00216208:11320/16:10325909 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.4171/JEMS/602" target="_blank" >http://dx.doi.org/10.4171/JEMS/602</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4171/JEMS/602" target="_blank" >10.4171/JEMS/602</a>

Result language

angličtina

Original language name

Coherent randomness tests and computing the K-trivial sets

Original language description

We introduce Oberwolfach randomness, a notion within Demuth's framework of statistical tests with moving components; here the components' movement has to be coherent across levels. We show that a ML-random set computes all K-trivial sets if and only if it is not Oberwolfach random, and indeed there is a K-trivial set which is not computable from any Oberwolfach random set. We show that Oberwolfach random sets satisfy effective versions of almost-everywhere theorems of analysis, such as the Lebesgue density theorem and Doob's martingale convergence theorem. We also show that random sets which are not Oberwolfach random satisfy highness properties (such as LR-hardness) which mean they are close to computing the halting problem. A consequence of these results is that a ML-random set failing the effective version of Lebesgue's density theorem for closed sets must compute all K-trivial sets. Combined with a recent result by Day and Miller, this gives a positive solution to the ML-covering problem of algorithmic randomness. On the other hand these results settle stronger variants of the covering problem in the negative: no low ML-random set computes all K-trivial sets, and not every K-trivial set is computable from both halves of a random set.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

IN - Informatics

OECD FORD branch

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Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of the European Mathematical Society

ISSN

1435-9855

e-ISSN

—

Volume of the periodical

18

Issue of the periodical within the volume

4

Country of publishing house

DE - GERMANY

Number of pages

40

Pages from-to

773-812

UT code for WoS article

000371990000003

EID of the result in the Scopus database

2-s2.0-84961839155