Exotic group C*-algebras of higher rank Lie groups

An exotic group C*-algebra is a C*-algebra that lies naturally between the reduced and the universal group C*-algebra. In this thesis we study the existence of such C*-algebras for the special linear groups over the complex numbers and for the symplectic group, as examples of connected simple Lie gr...

Verfasser: Dabeler, Antje
Weitere Beteiligte: Laat, Tim de (Gutachter)
FB/Einrichtung:FB 10: Mathematik und Informatik
Dokumenttypen:Dissertation/Habilitation
Medientypen:Text
Erscheinungsdatum:2023
Publikation in MIAMI:25.05.2023
Datum der letzten Änderung:08.11.2023
Angaben zur Ausgabe:[Electronic ed.]
Schlagwörter:Group C*-algebras; Representation theory; Operator algebras; Lie groups; Kunze-Stein property
Fachgebiet (DDC):510: Mathematik
Lizenz:CC BY 4.0
Sprache:English
Hochschulschriftenvermerk:Münster (Westfalen), Univ., Diss., 2023
Format:PDF-Dokument
URN:urn:nbn:de:hbz:6-50029406326
Weitere Identifikatoren:DOI: 10.17879/50029406524
Permalink:https://nbn-resolving.de/urn:nbn:de:hbz:6-50029406326
Onlinezugriff:diss_dabeler.pdf
LEADER 04715cam a2200361uu 4500
001 9915007d-405a-4a13-a757-dc832ea7b0b7
003 miami
005 20231108
007 c||||||||||||a|
008 230525e20230525||||||||||#s||||||||eng||||||
024 7 |a urn:nbn:de:hbz:6-50029406326  |2 urn 
024 7 |a 10.17879/50029406524  |2 doi 
041 |a eng 
082 0 |a 510 Mathematik  |2 23 
100 1 |a Dabeler, Antje  |0 http://d-nb.info/gnd/1291235477  |4 aut 
110 2 |a Universitäts- und Landesbibliothek Münster  |0 http://d-nb.info/gnd/5091030-9  |4 own 
245 1 0 |a Exotic group C*-algebras of higher rank Lie groups 
250 |a [Electronic ed.] 
264 1 |c 2023 
264 2 |b Universitäts- und Landesbibliothek Münster  |c 2023-05-25 
300 |a ii, 78 
502 |a Münster (Westfalen), Univ., Diss., 2023 
505 0 |a 1 Introduction 1 -- 2 Completions and unitary duals 7 -- 2.1 Ideal completions and Lp-completions . . . . . . . . . . . . . . . . . . . . 7 -- 2.2 Exotic group C∗-algebras of discrete groups . . . . . . . . . . . . . . . . . 14 -- 2.3 Kunze–Stein property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 -- 2.4 Strategy to find exotic group C∗-algebras . . . . . . . . . . . . . . . . . . 23 -- 3 Structure theory of Lie groups 26 -- 3.1 Iwasawa decomposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 -- 3.2 Root systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 -- 3.3 Gelfand pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 -- 4 Representation theory of Lie groups 35 -- 4.1 Parabolic induction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 -- 4.2 Infinitesimal character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 -- 4.3 Asymptotic expansion of spherical representations . . . . . . . . . . . . . 40 -- 4.4 Representation theory of SL(n,C) . . . . . . . . . . . . . . . . . . . . . . 45 -- 4.4.1 Stein complementary series . . . . . . . . . . . . . . . . . . . . . . 45 -- 4.4.2 Vogan’s description of the unitary dual of GL(n,C) . . . . . . . . . 47 -- 4.4.3 Duflo’s description of parabolically induced representations . . . . 48 -- 5 Exotic group C∗-algebras 53 -- 5.1 Exotic group C∗-algebras of SL(2,C) . . . . . . . . . . . . . . . . . . . . . 53 -- 5.2 Representations with minimal decay . . . . . . . . . . . . . . . . . . . . . 54 -- 5.3 Exotic group C∗-algebras of SL(n,C) . . . . . . . . . . . . . . . . . . . . . 55 -- 5.3.1 Some low-dimensional cases . . . . . . . . . . . . . . . . . . . . . . 55 -- 5.3.2 Integrability properties of the Stein complementary series . . . . . 59 -- 5.4 Exotic group C∗-algebras of Sp(2,C) . . . . . . . . . . . . . . . . . . . . . 63 -- 5.5 Lp+-representations of colored Neretin groups . . . . . . . . . . . . . . . . 66 -- 6 Outlook 71 -- 6.1 Other higher rank Lie groups . . . . . . . . . . . . . . . . . . . . . . . . . 71 -- 6.2 Induction from closed subgroups . . . . . . . . . . . . . . . . . . . . . . . 72 -- Bibliography 74 -- . 
506 0 |a free access 
520 3 |a An exotic group C*-algebra is a C*-algebra that lies naturally between the reduced and the universal group C*-algebra. In this thesis we study the existence of such C*-algebras for the special linear groups over the complex numbers and for the symplectic group, as examples of connected simple Lie groups with real rank greater or equal than 2. In both cases we are able to show the existence of a continuum of exotic group C*-algebras. In joint work with Emilie Elkiær, Maria Gerasimova and Tim de Laat we studied induction of unitary representations from an open subgroup H in a locally compact group G. We observed that in this case exotic group C*-algebras of H give rise to exotic group C*-algebras of G. If H further has the Kunze-Stein property, it is moreover possible to deduce the existence of representations of G with specific integrability properties from the existence of such representations of H. 
521 |a specialized 
540 |a CC BY 4.0  |u http://creativecommons.org/licenses/by/4.0/ 
653 0 |a Group C*-algebras  |a Representation theory  |a Operator algebras  |a Lie groups  |a Kunze-Stein property 
655 7 |2 DRIVER Types  |a Dissertation/Habilitation 
655 7 |2 DCMI Types  |a Text 
700 1 |a Laat, Tim de  |u FB 10: Mathematik und Informatik  |0 http://d-nb.info/gnd/1237544629  |0 http://viaf.org/viaf/6376162723669861290008  |4 ths 
856 4 0 |3 Zum Volltext  |q text/html  |u https://nbn-resolving.de/urn:nbn:de:hbz:6-50029406326  |u urn:nbn:de:hbz:6-50029406326 
856 4 0 |3 Zum Volltext  |q application/pdf  |u https://repositorium.uni-muenster.de/document/miami/9915007d-405a-4a13-a757-dc832ea7b0b7/diss_dabeler.pdf