Abstract:
The matrix of a permutation is a partial case of Markov transition matrices. In the same way, a measure preserving bijection of a space (A,α) with finite measure is a partial case of Markov transition operators. A Markov transition operator also can be considered as a map (polymorphism) (A,α)→(A,α),
which spreads points of (A,α) into measures on (A,α).
Denote by R∗ the multiplicative group of positive real numbers and by M the semigroup of measures on R∗. In this paper, we discuss R∗-polymorphisms
and ⋎-polymorphisms, who are analogues of the Markov transition operators (or polymorphisms) for the groups of bijections (A,α)→(A,α) leaving the measure α quasiinvariant; two types of the polymorphisms correspond to the cases, when A has finite and infinite measure respectively. For the case, when the space A itself is finite, the R∗-polymorphisms are some M-valued matrices.
We construct a functor from ⋎-polymorphisms to R∗-polymorphisms, it is described in terms of summations of M-convolution products over matchings of Poisson configurations.
Citation:
Yu. A. Neretin, “Spreading maps (polymorphisms), symmetries of Poisson processes, and matching summation”, Representation theory, dynamical systems, combinatorial and algoritmic methods. Part VII, Zap. Nauchn. Sem. POMI, 292, POMI, St. Petersburg, 2002, 62–91; J. Math. Sci. (N. Y.), 126:2 (2005), 1077–1094
\Bibitem{Ner02}
\by Yu.~A.~Neretin
\paper Spreading maps (polymorphisms), symmetries of Poisson processes, and matching summation
\inbook Representation theory, dynamical systems, combinatorial and algoritmic methods. Part~VII
\serial Zap. Nauchn. Sem. POMI
\yr 2002
\vol 292
\pages 62--91
\publ POMI
\publaddr St.~Petersburg
\mathnet{http://mi.mathnet.ru/znsl1667}
\mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=1944085}
\zmath{https://zbmath.org/?q=an:1079.28008}
\transl
\jour J. Math. Sci. (N. Y.)
\yr 2005
\vol 126
\issue 2
\pages 1077--1094
\crossref{https://doi.org/10.1007/s10958-005-0089-z}
Linking options:
https://www.mathnet.ru/eng/znsl1667
https://www.mathnet.ru/eng/znsl/v292/p62
This publication is cited in the following 8 articles:
Yu. A. Neretin, “Polyhomomorphisms of locally compact groups”, Sb. Math., 212:2 (2021), 185–210
Yu. A. Neretin, “Wishart–Pickrell distributions and closures of group actions”, J. Math. Sci. (N. Y.), 224:2 (2017), 328–334
Yu. A. Neretin, “Infinite symmetric groups and combinatorial constructions of topological field theory type”, Russian Math. Surveys, 70:4 (2015), 715–773
Yu. A. Neretin, “Bi-invariant functions on the group of transformations leaving a measure quasi-invariant”, Sb. Math., 205:9 (2014), 1357–1372
Yu. A. Neretin, “On the boundary of the group of transformations leaving a measure quasi-invariant”, Sb. Math., 204:8 (2013), 1161–1194
Yu. Neretin, “Infinite Tri-symmetric Group, Multiplication of Double Cosets, and Checker Topological Field Theories”, International Mathematics Research Notices, 2012:3 (2012), 501
Yury Neretin, “Symmetries of Gaussian measures and operator colligations”, Journal of Functional Analysis, 263:3 (2012), 782
Salvai M., “A dynamical approach to compactify the three dimensional Lorentz group”, J Lie Theory, 15:1 (2005), 335–339