Abstract:
Given disjoint countable dense subsets $C$ and $D$ of the half-line $(1,+\infty)$,
there exists a flow $T_t$ preserving a sigma-finite measure and such that
all automorphisms $T_1\otimes T_{c}$ with $c\in C$ have simple singular spectrum and
all automorphisms $T_1\otimes T_{d}$ with $d\in D$ have Lebesgue spectrum of countable multiplicity.
Keywords:tensor product of flows,
absolutely continuous singular spectrum, dissipativity, weak limits of operators.