Taiwanese Journal of Mathematics


Aoi Honda, Yoshiaki Okazaki, and Hiroshi Sato

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Let $\bf X=\{X_k\}$ be an IID random sequence and $\bf Y=\{Y_k\}$ be an independent random sequence also independent of $\bf X$. Denote by $\mu_{\bf X}$ and $\mu_{\bf X+\bf Y}$ the probability measures on the sequence space induced by $\bf X$ and $\bf X+\bf Y =\{X_k+Y_k\}$, respectively. The problem is to characterize $\mu_{\bf X+\bf Y}\sim\mu_{\bf X}$ in terms of $\mu_{\bf Y}$ in the case where $\bf X$ is non-negative. Sato and Tamashiro [6] first discussed this problem assuming the existence of ${f_{\bf X}(x)=\frac{d\mu_{X_1}}{dx}(x)}$. They gave several necessary or sufficient conditions for $\mu_{\bf X+\bf Y}\sim\mu_{\bf X}$ under some additional assumptions on $f_{\bf X}$ or on $\bf Y$. The authors precisely improve these results. First they rationalize the assumption of the existence of $f_{\bf X}$. Then they prove that the condition (C.6) is necessary for wider classes of $f_\bf X$ with local regularities. They also prove if the $p$-integral $I_p^0(\bf X)\lt \infty$ and $\bf Y\in \ell_p^+$ a.s., then (C.6) is necessary and sufficient. Furthermore, in the typical case where $\bf X$ is exponentially distributed, they prove an explicit necessary and sufficient condition for $\mu_{\bf X+\bf Y}\sim \mu_\bf X$.

Article information

Taiwanese J. Math., Volume 13, Number 1 (2009), 269-286.

First available in Project Euclid: 18 July 2017

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Zentralblatt MATH identifier

Primary: 60G30: Continuity and singularity of induced measures 28C20: Set functions and measures and integrals in infinite-dimensional spaces (Wiener measure, Gaussian measure, etc.) [See also 46G12, 58C35, 58D20, 60B11]
Secondary: 60B11: Probability theory on linear topological spaces [See also 28C20] 46G12: Measures and integration on abstract linear spaces [See also 28C20, 46T12]

non-negative random translates admissible Kakutani's dichotomy theorem Kitada-Sato criterion $p$-integral exponential distribution


Honda, Aoi; Okazaki, Yoshiaki; Sato, Hiroshi. EQUIVALENCE OF NON-NEGATIVE RANDOM TRANSLATES OF AN IID RANDOM SEQUENCE. Taiwanese J. Math. 13 (2009), no. 1, 269--286. doi:10.11650/twjm/1500405283. https://projecteuclid.org/euclid.twjm/1500405283

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