L2-Singular Dichotomy for Orbital Measures on Complex Groups
Gupta, S. K. ; Hare, K. E.
Bollettino dell'Unione Matematica Italiana, Tome 3 (2010), p. 409-419 / Harvested from Biblioteca Digitale Italiana di Matematica

It is known that all continuous orbital measures, μ on a compact, connected, classical simple Lie group G or its Lie algebra satisfy a dichotomy: either μkL2 or μk is purely singular to Haar measure. In this note we prove that the same dichotomy holds for the dual situation, continuous orbital measures on the complex group GC. We also determine the sharp exponent k such that any k-fold convolution product of continuous G-bi-invariant measures on GC is absolute continuous with respect to Haar measure.

Publié le : 2010-10-01
@article{BUMI_2010_9_3_3_409_0,
     author = {S. K. Gupta and K. E. Hare},
     title = {$L^{2}$-Singular Dichotomy for Orbital Measures on Complex Groups},
     journal = {Bollettino dell'Unione Matematica Italiana},
     volume = {3},
     year = {2010},
     pages = {409-419},
     zbl = {1217.22008},
     mrnumber = {2742774},
     language = {en},
     url = {http://dml.mathdoc.fr/item/BUMI_2010_9_3_3_409_0}
}
Gupta, S. K.; Hare, K. E. $L^{2}$-Singular Dichotomy for Orbital Measures on Complex Groups. Bollettino dell'Unione Matematica Italiana, Tome 3 (2010) pp. 409-419. http://gdmltest.u-ga.fr/item/BUMI_2010_9_3_3_409_0/

[1] Knapp, A. W., Lie Groups beyond an introduction, Birkhauser Verlag AG (2002). | MR 1920389 | Zbl 1075.22501

[2] Dooley, A. - Ricci, F., Characterisation of G-invariant Fourier algebras, Un. Boll. Mat. Ital., 9 (1995), 37-45. | MR 1324602 | Zbl 0836.43008

[3] Gupta, S. - Hare, K., Singularity of orbits in classical Lie algebras, Geom. Func. Anal., 13 (2003), 815-844. | MR 2006558 | Zbl 1031.22004

[4] Gupta, S. - Hare, K., L2-singular dichotomy for orbital measures of classical compact Lie groups, Adv. Math, 222 (2009), 1521-1573. | MR 2555904 | Zbl 1179.43006

[5] Gupta, S., - Hare, K. - Seyfaddini, S., L2-singular dichotomy for orbital measures of classical simple Lie algebras, Math. Zeit., 262 (2009), 91-124. | MR 2491602 | Zbl 1168.43003

[6] Helgason, S., Differential geometry, Lie groups and symmetric spaces, Academic Press, New York (1978). | MR 514561 | Zbl 0451.53038

[7] Ragozin, D., Central measures on compact simple Lie groups, J. Func. Anal., 10 (1972), 212-229. | MR 340965 | Zbl 0286.43002

[8] Ragozin, D., Zonal measure algebras on isotropy irreducible homogeneous spaces, J. Func. Anal., 17 (1974), 355-376. | MR 365044 | Zbl 0297.43002

[9] Ricci, F. - Stein, E., Harmonic analysis on nilpotent groups and singular integrals II. Singular kernels supported on submanifolds, J. Func. Anal., 78 (1988), 56-84. | MR 937632 | Zbl 0645.42019

[10] Varadarajan, V. S., Lie groups and Lie algebras and their representations, Springer-Verlag, New York (1984). | MR 746308 | Zbl 0955.22500