Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-11T04:06:35.608Z Has data issue: false hasContentIssue false

Computational randomness and lowness*

Published online by Cambridge University Press:  12 March 2014

Sebastiaan A. Terwijn
Affiliation:
Department of Mathematics and Computer Science, Free University of Amsterdam, de Boelelaan 1081 a, 1081 HV Amsterdam, The Netherlands, E-mail: terwijn@cs.vu.nl
Domenico Zambella
Affiliation:
Department of Mathematics, University of Torino, VIA Carlo Alberto 10, 10123 Torino, Italy, E-mail: domenico@dm.unito.it

Abstract

We prove that there are uncountably many sets that are low for the class of Schnorr random reals. We give a purely recursion theoretic characterization of these sets and show that they all have Turing degree incomparable to 0′. This contrasts with a result of Kučera and Terwijn [5] on sets that are low for the class of Martin-Löf random reals.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

*

Research supported by the Netherlands Foundation for Scientific Research (NWO) Project PGS 22-262. Most of this research was done while the authors were working at the University of Amsterdam.

References

REFERENCES

[1]Ambos-Spies, K. and Kučera, A., Randomness in computability theory, Computability theory and its applications: Current trends and open problems (Cholak, P., Lempp, S., Lerman, M., and Shore, R. A., editors), Contemporary Mathematics, vol. 257, AMS, Providence RI, 2000, pp. 114.CrossRefGoogle Scholar
[2]Ambos-Spies, K. and Mayordomo, E., Resource-bounded measure and randomness, Complexity, logic, and recursion theory (Sorbi, A., editor), Lecture Notes in Pure and Applied Mathematics, Marcel Dekker, New York, 1997, pp. 147.Google Scholar
[3]Demuth, O. and Kučera, A., Remarks on constructive mathematical analysis, Logic colloquium '78 (Boffe, M., van Dalen, D., and McAloon, K., editors), North-Holland, 1979, pp. 81129.Google Scholar
[4]Kučera, A., Measure, Π10-classes, and complete extensions of PA, Recursion Theory Week 1984 (Ebbinghaus, H.-D., Müller, G. H., and Sacks, G. E., editors), Lecture Notes in Mathematics, vol. 1141, Springer-Verlag, 1985, pp. 245259.CrossRefGoogle Scholar
[5]Kučera, A. and Terwijn, S. A., Lownessfor the class of random sets, this Journal, vol. 64 (1999), no. 4, pp. 13961402.Google Scholar
[6]van Lambalgen, M., Random sequences, Ph.D. thesis, University of Amsterdam, 1987.Google Scholar
[7]Martin-Löf, P., The definition of random sequences, Information and Control, vol. 9 (1966), pp. 602619.CrossRefGoogle Scholar
[8]Miller, W. and Martin, D. A., The degrees of hyperimmune sets, Z. Math. Logik Grundlagen Math, vol. 14 (1968), pp. 159166.CrossRefGoogle Scholar
[9]Odifreddi, P., Classical recursion theory, North-Holland, 1989.Google Scholar
[10]Raisonnier, J., A mathematical proof of S. Shelah's theorem on the measure problem and related results, Israel Journal of Mathematics, vol. 48 (1984), pp. 4856.CrossRefGoogle Scholar
[11]Schnorr, C.-P., Zufälligkeit und Wahrscheinlichkeit, Lecture Notes in Mathematics, vol. 218, Springer-Verlag, 1971.CrossRefGoogle Scholar