Editing Compact group (section)

==From compact to non-compact groups==

The influence of the compact group theory on non-compact groups was formulated by Weyl in his [[unitarian trick]]. Inside a general [[semisimple Lie group]] there is a [[maximal compact subgroup]], and the representation theory of such groups, developed largely by [[Harish-Chandra]], uses intensively the [[restriction of a representation]] to such a subgroup, and also the model of Weyl's character theory.