Distribution of recursive matrix pseudorandom number generator modulo prime powers

Abstract: Given a matrix $A\in \mathrm{GL}d(\mathbb{Z})$. We study the pseudorandomness of vectors $\mathbf{u}_n$ generated by a linear recurrent relation of the form $$ \mathbf{u}{n+1} \equiv A \mathbf{u}_n \pmod {p^t}, \qquad n = 0, 1, \ldots, $$ modulo $p^t$ with a fixed prime $p$ and sufficiently large integer $t \geq 1$. We study such sequences over very short segments of length which is not accessible via previously used methods. Our technique is based on the method of N. M. Korobov (1972) of estimating double Weyl sums and a fully explicit form of the Vinogradov mean value theorem due to K. Ford (2002). This is combined with some ideas from the work of I. E. Shparlinski (1978) which allows to construct polynomial representations of the coordinates of $\mathbf{u}_n$ and control the $p$-adic orders of their coefficients in polynomial representation.