The complementary group of proper motions of the Minkowski metric in an   arbitrary dimension space
  It is shown that the Poincare group which is a semidirect product of the group of translations and the Lorentz group, is not a single physicaly important group of proper motions of Minkowski metric. The complementary group of proper motions of the metric in a class of noninertial reference system has been found. 
Nikolay Popov