In mathematics, the Trombi–Varadarajan theorem, introduced by Trombi and Varadarjan (1971), gives an isomorphism between a certain space of spherical functions on a semisimple Lie group, and a certain space of holomorphic functions defined on a tubular neighborhood of the dual of a Cartan subalgebra.
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Trombi–Varadarajan theorem Wikipedia(Text) CC BY-SA