Compositionality

The open-access journal for the mathematics of composition

Infinite products and zero-one laws in categorical probability

Tobias Fritz1 and Eigil Fjeldgren Rischel2

1Deparment of Mathematical Sciences, University of Copenhagen, 2100 Denmark
2Perimeter Institute for Theoretical Physics, N2L 2Y5, Waterloo, Ontario, Canada

Updated version: The authors have uploaded version v6 of this work to the arXiv which may contain updates or corrections not contained in the published version v5. The authors left the following comment on the arXiv:
20 pages. v6: Some minor fixes

ABSTRACT

Markov categories are a recent category-theoretic approach to the foundations of probability and statistics. Here we develop this approach further by treating infinite products and the Kolmogorov extension theorem. This is relevant for all aspects of probability theory in which infinitely many random variables appear at a time. These infinite tensor products $\bigotimes_{i \in J} X_i$ come in two versions: a weaker but more general one for families of objects $(X_i)_{i \in J}$ in semicartesian symmetric monoidal categories, and a stronger but more specific one for families of objects in Markov categories.

As a first application, we state and prove versions of the zero--one laws of Kolmogorov and Hewitt--Savage for Markov categories. This gives general versions of these results which can be instantiated not only in measure-theoretic probability, where they specialize to the standard ones in the setting of standard Borel spaces, but also in other contexts.

► BibTeX data

► References

[1] Erik Sparre Andersen and Børge Jessen. On the introduction of measures in infinite product sets. Kongelige Danske Videnskabernes Selskab, Matematiske-Fysiske meddelelser, 25(4):8, 1948.

[2] Bruce E. Blackadar. Infinite tensor products of $C\sp*$-algebras. Pacific Journal of Mathematics, 72(2):313–334, 1977.

[3] Kenta Cho and Bart Jacobs. Disintegration and Bayesian inversion via string diagrams. Mathematical Structures in Computer Science, 29:938–971, 2019. https:/​/​doi.org/​10.1017/​S0960129518000488.
https:/​/​doi.org/​10.1017/​S0960129518000488

[4] Pierre Deligne, James S. Milne, Arthur Ogus, and Kuang-yen Shih. Hodge cycles, motives, and Shimura varieties, volume 900 of Lecture Notes in Mathematics. Springer-Verlag, Berlin-New York, 1982. https:/​/​doi.org/​10.1007/​978-3-540-38955-2.
https:/​/​doi.org/​10.1007/​978-3-540-38955-2

[5] D. H. Fremlin. Measure theory. Vol. 4. Torres Fremlin, Colchester, 2006. Topological measure spaces. Part I, II, Corrected second printing of the 2003 original. https:/​/​www1.essex.ac.uk/​maths/​people/​fremlin/​mt.htmwww1.essex.ac.uk/​maths/​people/​fremlin/​mt.htm.
https:/​/​www1.essex.ac.uk/​maths/​people/​fremlin/​mt.htm

[6] Tobias Fritz. A synthetic approach to Markov kernels, conditional independence and theorems on sufficient statistics. https:/​/​doi.org/​10.1016/​j.aim.2020.107239.
https:/​/​doi.org/​10.1016/​j.aim.2020.107239

[7] Tobias Fritz, Paolo Perrone, and Sharwin Rezagholi. Probability, valuations, hyperspace: Three monads on top and the support as a morphism. ArXiv, abs/​1910.03752, 2019.

[8] Malte Gerhold, Stephanie Lachs, and Michael Schürmann. Categorial Lévy processes. https:/​/​arxiv.org/​abs/​1612.05139arXiv:1612.05139.
arXiv:1612.05139

[9] Michèle Giry. A categorical approach to probability theory. In Categorical aspects of topology and analysis (Ottawa, Ont., 1980), volume 915 of Lecture Notes in Mathematics, pages 68–85. Springer, 1982. https:/​/​doi.org/​10.1007/​BFb0092872.
https:/​/​doi.org/​10.1007/​BFb0092872

[10] Peter V. Golubtsov. Axiomatic description of categories of information converters. Problemy Peredachi Informatsii, 35(3):80–98, 1999. In Russian. English translation in Problems of Information Transmission 35(3):259–274, 1999.

[11] Edwin Hewitt and Leonard J. Savage. Symmetric measures on cartesian products. Transactions of the American Mathematical Society, 80(2):470–470, February 1955. https:/​/​doi.org/​10.1090/​s0002-9947-1955-0076206-8.
https:/​/​doi.org/​10.1090/​s0002-9947-1955-0076206-8

[12] Georg Karner. Continuous monoids and semirings. Theoretical Computer Science, 318(3):355–372, 2004. https:/​/​doi.org/​10.1016/​j.tcs.2004.01.020.
https:/​/​doi.org/​10.1016/​j.tcs.2004.01.020

[13] Achim Klenke. Probability theory, a comprehensive course. Universitext. Springer, London, second edition, 2014. https:/​/​doi.org/​10.1007/​978-1-4471-5361-0.
https:/​/​doi.org/​10.1007/​978-1-4471-5361-0

[14] A. N. Kolmogorov. Grundbegriffe der Wahrscheinlichkeitsrechnung. Springer, Berlin, 1933.

[15] D. Ramachandran. Perfect mixtures of perfect measures. Annals of Probability, 7(3):444–452, 1979. https:/​/​doi.org/​10.1214/​aop/​1176995045.
https:/​/​doi.org/​10.1214/​aop/​1176995045

[16] Andrea Schalk. Algebras for generalized power constructions. PhD thesis, University of Darmstadt, 1993. Available at www.cs.man.ac.uk/​ schalk/​publ/​diss.ps.gzwww.cs.man.ac.uk/​ schalk/​publ/​diss.ps.gz.
http:/​/​www.cs.man.ac.uk/​~schalk/​publ/​diss.ps.gz

Cited by

Could not fetch Crossref cited-by data during last attempt 2024-11-05 00:02:38: Could not fetch cited-by data for 10.32408/compositionality-2-3 from Crossref. This is normal if the DOI was registered recently. On SAO/NASA ADS no data on citing works was found (last attempt 2024-11-05 00:02:38).