Improving the Lieb-Robinson bound for long-range interactions
  We improve the Lieb-Robinson bound for a wide class of quantum many-body systems with long-range interactions decaying by power law. As an application, we show that the group velocity of information propagation grows by power law in time for such systems, whereas systems with short-range interactions exhibit a finite group velocity as shown by Lieb and Robinson. 
T. Matsuta, T. Koma, S. Nakamura
math-ph math.FA math.MP