It is known that all continuous orbital measures, on a compact, connected, classical simple Lie group or its Lie algebra satisfy a dichotomy: either or 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 . We also determine the sharp exponent such that any -fold convolution product of continuous -bi-invariant measures on is absolute continuous with respect to Haar measure.
@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/
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