  For a function $\varphi$ in $L^2(0,1)$, extended to the whole real line as an
odd periodic function of period 2, we ask when the collection of dilates
$\varphi(nx)$, $n=1,2,3,\ldots$, constitutes a Riesz basis or a complete
sequence in $L^2(0,1)$. The problem translates into a question concerning
multipliers and cyclic vectors in the Hilbert space $\cal H$ of Dirichlet
series $f(s)=\sum_n a_nn^{-s}$, where the coefficients $a_n$ are square
summable. It proves useful to model $\cal H$ as the $H^2$ space of the
infinite-dimensional polydisk, or, which is the same, the $H^2$ space of the
character space, where a character is a multiplicative homomorphism from the
positive integers to the unit circle. For given $f$ in $\cal H$ and characters
$\chi$, $f_\chi(s)=\sum_na_n\chi(n)n^{-s}$ is a vertical limit function of $f$.
We study certain probabilistic properties of these vertical limit functions.
