Published online by Cambridge University Press: 18 February 2021
It is proved that each Gaussian cocycle over a mildly mixing Gaussian transformation is either a Gaussian coboundary or sharply weak mixing. The class of non-singular infinite direct products T of transformations
$T_n$
,
$n\in \mathbb N$
, of finite type is studied. It is shown that if
$T_n$
is mildly mixing,
$n\in \mathbb N$
, the sequence of Radon–Nikodym derivatives of
$T_n$
is asymptotically translation quasi-invariant and T is conservative then the Maharam extension of T is sharply weak mixing. This technique provides a new approach to the non-singular Gaussian transformations studied recently by Arano, Isono and Marrakchi.
To the memory of Sergiy Sinel’shchikov, our colleague and friend