Source: J. Symbolic Logic Volume 75, Issue 2
(2010), 501-521.
We give several characterizations of Schnorr trivial
sets, including a new lowness notion for Schnorr triviality based on
truth-table reducibility. These characterizations allow us to
see not only that some natural classes of sets, including maximal
sets, are composed entirely of Schnorr trivials, but also that the
Schnorr trivial sets form an ideal in the truth-table degrees but not
the weak truth-table degrees. This answers a question of Downey,
Griffiths and LaForte.
References
Marat Arslanov, On some generalizations of a fixed-point theorem, Soviet Mathematics, vol. 25 (1981), no. 5, pp. 9--16, English translation, Izvestiya Vysshikh Uchebnykh Zavedeniĭ. Matematika, vol. 25 (1981), no. 5, pp. 1--10, Russian.
Mathematical Reviews (MathSciNet):
MR630478
Cristian S. Calude and André Nies, Chaitin $\Omega$ numbers and strong reducibilities, Journal of Universal Computer Science, vol. 3 (1997), pp. 1162--1166.
Rod Downey, Evan Griffiths, and Geoffrey LaForte, On Schnorr and computable randomness, martingales, and machines, Mathematical Logic Quarterly, vol. 50 (2004), pp. 613--627.
Rod Downey, Denis R. Hirschfeldt, André Nies, and Sebastiaan A. Terwijn, Calibrating randomness, Bulletin of Symbolic Logic, vol. 12 (2006), pp. 411--491.
Johanna N. Y. Franklin, Aspects of Schnorr randomness, Ph.D. dissertation, University of California, Berkeley, 2007.
--------, Hyperimmune-free degrees and Schnorr triviality, Journal of Symbolic Logic, vol. 73 (2008), pp. 999--1008.
--------, Schnorr trivial reals: A construction, The Archive for Mathematical Logic, vol. 46 (2008), pp. 665--678.
--------, Schnorr triviality and genericity, Journal of Symbolic Logic, vol. 75 (2010), pp. 191--207.
Denis Hirschfeldt, André Nies, and Frank Stephan, Using random sets as oracles, Journal of the London Mathematical Society, vol. 75 (2007), pp. 610--622.
Carl G. Jockusch and Frank Stephan, A cohesive set which is not high, Mathematical Logic Quarterly, vol. 39 (1993), pp. 515--530, A corrective note (keeping the main results intact) appeared in the same journal, vol. 43 (1997), p. 569.
Ming Li and Paul Vitányi, An introduction to Kolmogorov complexity and its applications, Springer, Heidelberg, 1993.
Per Martin-Löf, The definition of random sequences, Information and Control, vol. 9 (1966), pp. 602--619.
Mathematical Reviews (MathSciNet):
MR223179
Nenad Mihailović, Algorithmic randomness, Inaugural-Dissertation, University of Heidelberg, 2007.
Webb Miller and Donald Martin, The degrees of hyperimmune sets, Zeitschrift für Mathematische Logik und Grundlagen der Mathematik, vol. 14 (1968), pp. 159--166.
Mathematical Reviews (MathSciNet):
MR228341
André Nies, Lowness properties of reals and randomness, Advances in Mathematics, vol. 197 (2005), pp. 274--305.
André Nies, Frank Stephan, and Sebastiaan A. Terwijn, Randomness, relativization and Turing degrees, Journal of Symbolic Logic, vol. 70 (2005), pp. 515--535.
Piergiorgio Odifreddi, Classical recursion theory, North-Holland, Amsterdam, 1989.
Mathematical Reviews (MathSciNet):
MR982269
--------, Classical recursion theory, Volume II, North-Holland, Amsterdam, 1999.
Hartley Rogers, Theory of recursive functions and effective computability, McGraw-Hill, New York, 1967.
Mathematical Reviews (MathSciNet):
MR224462
Gerald E. Sacks, A maximal set which is not complete, Michigan Mathematical Journal, vol. 11 (1964), pp. 193--205.
Mathematical Reviews (MathSciNet):
MR166090
Claus Peter Schnorr, Zufälligkeit und Wahrscheinlichkeit, Lecture Notes in Mathematics, vol. 218, Springer, 1971.
Mathematical Reviews (MathSciNet):
MR414225
--------, Process complexity and effective random tests, Journal of Computer and System Sciences, vol. 7 (1973), pp. 376--388.
Mathematical Reviews (MathSciNet):
MR325366
Robert Soare, Recursively enumerable sets and degrees. A study of computable functions and computably generated sets, Springer-Verlag, Heidelberg, 1987.
Mathematical Reviews (MathSciNet):
MR882921
Frank Stephan, The complexity of the set of nonrandom numbers, Randomness and complexity, from Leibnitz to Chaitin (Cristian S. Calude, editor), vol. 217--230, World Scientific, 2007.