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Some sets with measurable inverses

Published online by Cambridge University Press:  24 October 2008

Roy O. Davies
Affiliation:
Leicester University and University College, London

Extract

Goldman (4) conjectured that if Z is a linear set having the property that for every (Lebesgue) measurable real function f the set f−1[Z] is a measurable set, then Z must be a Borel set. I pointed out (2) that any analytic non-Borel set provides a counterexample, and Eggleston(3) showed that a set can have the property but be neither analytic nor even an analytic complement, for example, any Luzin set. As Eggleston mentions, in the construction of Luzin sets the continuum hypothesis is assumed (compare Sierpiński(6), Chapter II), and the question arises whether it can be dispensed with in his theorem. We shall show that a non-analytic set having Goldman's property can be constructed with the help of the axiom of choice alone, without the continuum hypothesis; the problem for analytic complements remains open. We shall also generalize one of Eggleston's intermediate results.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1969

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References

REFERENCES

(1)Besicovitch, A. S.Relations between concentrated sets and sets possessing property C. Proc. Cambridge Philos. Soc. 38 (1942), 2023.Google Scholar
(2)Davies, Roy O.Remarks on measurable sets and functions. J. Res. Nat. Bur. Standards Sect. B 70B (1966), 8384.Google Scholar
(3)Eggleston, H. G.Concentrated sets. Proc. Cambridge Philos. Soc. 63 (1967), 931933.Google Scholar
(4)Goldman, A. J.On measurable sets and functions. J. Res. Nat. Bur. Standards Sect. B 69B (1965), 99100.CrossRefGoogle Scholar
(5)Hausdorff, F.Summen von ℵ1 Mengen. Fund. Math. 26 (1936), 241255.Google Scholar
(6)Sierpiński, W.Hypothèse du Continu (Warsaw-Lwow, 1934).Google Scholar
(7)Sierpiński, W. and Szpilrajn, E.Remarque sur le problème de la mesure. Fund. Math. 26 (1936), 256261.Google Scholar