On a standard product of an arbitrary family of $\sigma$-finite Borel measures with domains in Polish spaces
Gogi Pantsulaiaab a Institute of Applied Mathematics, Tbilisi State University, University Street-2, 0143 Tbilisi-43, Georgia
b Department of Mathematics, Georgian Technical University, Kostava Street-77, 0175 Tbilisi-75, Georgia
Аннотация:
Let
$\alpha$ be an infinite parameter set, and let
$(\alpha_i)_{i \in I}$ be its any partition such that
$\alpha_i$ is a non-empty finite subset for every
$i \in I.$ For
$j \in \alpha$, let
$\mu_j $ be a
$\sigma$-finite Borel measure defined on a Polish metric space
$(E_j,\rho_j)$. We introduce a concept of a standard
$(\alpha_i)_{i \in I}$-product of measures
$(\mu_j)_{j \in \alpha}$ and investigate its some properties. As a consequence, we construct "a standard
$(\alpha_i)_{i \in I}$-Lebesgue measure" on the Borel
$\sigma$-algebra of subsets of
$\mathbb{R}^{\alpha}$ for every infinite parameter set
$\alpha$ which is invariant under a group generated by shifts. In addition, if
${\rm card}(\alpha_i)=1$ for every
$i \in I$, then "a standard
$(\alpha_i)_{i \in I}$-Lebesgue measure"
$m^{\alpha}$ is invariant under a group generated by shifts and canonical permutations of
$\mathbb{R}^{\alpha}$. As a simple consequence, we get that a "standard Lebesgue measure"
$m^{\mathbb{N}}$ on
$\mathbb{R^N}$ improves R. Baker's measure
[2].
Ключевые слова:
Infinite-dimensional Lebesgue measure, product of
$\sigma$-finite measures.
MSC: Primary
28A35,
28Cxx,
28Dxx; Secondary
28C20,
28D10,
28D99
Язык публикации: английский