“…In the last two decades, it has been found that there exist locally rigid actions of higher dimensional Lie groups, and the rigidity theory of locally free actions have been rapidly developed. The reader can find examples of locally rigid or parameter rigid actions in many papers [5,9,10,11,12,49,51,18,24,32,33,36,41,42,52,53], some of which we will discuss in this article.…”