“…In this case, there have been a lot of works so far on the well-posedness of solutions to the Cauchy problem and the initialboundary-value problem for (1.1). Refer, for instance, to these elegant works [17,18,19,25,26,28,29,32] for local and global existence of classical solutions from one dimension to high dimensions. In particular, Matsumura and Nishida in [28,29] showed that the global classical solution in three dimensions exists provided that the initial data is small in H 3 .…”