On the similarity between the Iwasawa projection and the diagonal part
Analyse harmonique sur les groupes de Lie et les espaces symétriques (Actes du colloque du Kleebach, 20-24 mai 1983), Mémoires de la Société Mathématique de France, Série 2, no. 15 (1984), pp. 129-138. 
@incollection{MSMF_1984_2_15__129_0,
     author = {Duistermaat, J. J.},
     title = {On the similarity between the Iwasawa projection and the diagonal part},
     booktitle = {Analyse harmonique sur les groupes de Lie et les espaces sym\'etriques (Actes du colloque du Kleebach, 20-24 mai 1983)},
     editor = {Duflo, Michel and Eymard, Pierre and Schiffmann, G\'erard},
     series = {M\'emoires de la Soci\'et\'e Math\'ematique de France},
     pages = {129--138},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {15},
     year = {1984},
     doi = {10.24033/msmf.301},
     zbl = {0564.22007},
     mrnumber = {86k:22035},
     url = {http://archive.numdam.org/item/MSMF_1984_2_15__129_0/}
}
Duistermaat, J. J. On the similarity between the Iwasawa projection and the diagonal part, dans Analyse harmonique sur les groupes de Lie et les espaces symétriques (Actes du colloque du Kleebach, 20-24 mai 1983), Mémoires de la Société Mathématique de France, Série 2, no. 15 (1984), pp. 129-138. doi : 10.24033/msmf.301. http://archive.numdam.org/item/MSMF_1984_2_15__129_0/

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