Exact Results in Quantum Theory

In this short talk, I will present the problem of diverging expressions for velocity fluctuations in a stationary state of uniform sedimenting suspension. Those divergencies, as suggested by Koch and Shaqfeh, can be eliminated by plasma-like screening conditions for correlation functions. Unfortunately, BBGKY hierarchy for that system derived by Cichocki and Sadlej has problem to provide solutions that obey those conditions.