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Improved conditions for the distributivity of the product for σ-algebras with respect to the intersection

  • K. P. S. Bhaskara Rao and Alexander Steinicke EMAIL logo
Published/Copyright: May 24, 2024
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Abstract

We present a variety of refined conditions for σ-algebras 𝓐 (on a set X), 𝓕, 𝓖 (on a set U) such that the distributivity equation

( A F ) ( A G ) = A F G ,

holds – or is violated.

The article generalizes the results in an article of Steinicke (2021) and includes a positive result for σ-algebras generated by at most countable partitions, which was not covered before. We also present a proof that counterexamples may be constructed whenever X is uncountable and there exist two σ-algebras on X which are both countably separated, but their intersection is not. We present examples of such structures. In the last section, we extend Theorem 2 in Steinicke (2021) from analytic to the setting of Blackwell spaces.

  1. Communicated by Anatolij Dvurečenskij

References

[1] Aumann, R.: Borel structures for function spaces, Illinois J. Math. 5 (1961), 614–635.10.1215/ijm/1255631584Search in Google Scholar

[2] Basu, D.: Problems relating to the existence of maximal and minimal elements in some families of statistics (subfields). In: Proceedings of the Fifth Berkeley Symposium on Mathematical Statistics and Probability, Vol. 1: Statistics, 1967, pp. 41–50.Search in Google Scholar

[3] Bhaskara Rao, M.—Bhaskara Rao, K. P. S.: Borel σ-algebra on [0, Ω], Bull. Acad. Polon. Sci. 26 (1978), 767–769.Search in Google Scholar

[4] Bhaskara Rao, K. P. S.—Rao, B. V.: Borel Spaces, Warszawa, Instytut Matematyczny Polskiej Akademi Nauk, Dissertationes Mathematicae, Tom. CXC, 1981; http://eudml.org/doc/268562.Search in Google Scholar

[5] Bhaskara Rao, K. P. S.—Rao, B. V.: Mixtures of non-atomic measures II, Colloq. Math. 33(1) (1975), 105–112.10.4064/cm-33-1-105-112Search in Google Scholar

[6] Bhaskara Rao, K. P. S.—Bhaskara Rao, M.: A note on the countable chain condition and σ finiteness of measures, Bull. Aust. Math. Soc. 6 (1972), 349–353.10.1017/S0004972700044610Search in Google Scholar

[7] Bhaskara Rao, K. P. S.—Shortt, R. M.: Borel Spaces II, Warszawa, Instytut Matematyczny Polskiej Akademi Nauk, Dissertationes Mathematicae, Tom. CCCLXXII, 1997; https://eudml.org/doc/271126.Search in Google Scholar

[8] Blackwell, D.: On a class of probability spaces, 3rd Berkeley Symposium, Vol. 2, 1956, 1–6.10.1525/9780520350670-004Search in Google Scholar

[9] Georgiou, D.—Kougias, I.—Megaritis, A.: Borel structures on the set of Borel mappings, Topology Appl. 159(7) (2012), 1906–1915.10.1016/j.topol.2011.09.044Search in Google Scholar

[10] Grzegorek, E.: Remark on some Borel structures. In: Measure Theory Oberwolfach, Lecture Notes in Math., 1983, pp. 69–74.10.1007/BFb0072602Search in Google Scholar

[11] Kechris, A.: Classical Descriptive Set Theory, Springer, New York, 1994.10.1007/978-1-4612-4190-4Search in Google Scholar

[12] Mackey, G. W.: Borel structures in groups and their duals, Trans. Amer. Math. Soc. 85 (1957), 134–165.10.1090/S0002-9947-1957-0089999-2Search in Google Scholar

[13] Musiał, K.: Projective limits of perfect measure spaces, Fund. Math. 110(3) (1980).10.4064/fm-110-3-163-189Search in Google Scholar

[14] Parry, W.: Topics in Ergodics Theory, Cambridge University Press, 1981.Search in Google Scholar

[15] Rao, B. V.: On Borel structures, Colloq. Math. 21 (1970), 199–204.10.4064/cm-21-2-199-204Search in Google Scholar

[16] Mathematics Stack Exchange; https://math.stackexchange.com/questions/92546/decreasing-sequence-of-product-sigma-algebras, viewed on July 17, 2023.Search in Google Scholar

[17] Steinicke, A.: (Non-)distributivity of the product for σ-algebras with respect to the intersection, Arch. Math. (Basel) 116(6) (2021), 667–675.10.1007/s00013-020-01571-zSearch in Google Scholar

[18] Steinicke, A.: Functionals of a Lévy process on canonical and generic probability spaces, J. Theoret. Probab. 29(2) (2016), 443–458.10.1007/s10959-014-0583-7Search in Google Scholar

Received: 2023-05-10
Accepted: 2023-07-05
Published Online: 2024-05-24
Published in Print: 2024-04-25

© 2024 Mathematical Institute Slovak Academy of Sciences

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