%0 Journal Article %1 banica2009finetti %A Banica, Teodor %A Curran, Stephen %A Speicher, Roland %D 2009 %K probability theory %R 10.1214/10-AOP619 %T De Finetti theorems for easy quantum groups %U http://arxiv.org/abs/0907.3314 %X We study sequences of noncommutative random variables which are invariant under "quantum transformations" coming from an orthogonal quantum group satisfying the "easiness" condition axiomatized in our previous paper. For 10 easy quantum groups, we obtain de Finetti type theorems characterizing the joint distribution of any infinite quantum invariant sequence. In particular, we give a new and unified proof of the classical results of de Finetti and Freedman for the easy groups S_n, O_n, which is based on the combinatorial theory of cumulants. We also recover the free de Finetti theorem of Köstler and Speicher, and the characterization of operator-valued free semicircular families due to Curran. We consider also finite sequences, and prove an approximation result in the spirit of Diaconis and Freedman.

@article{banica2009finetti, abstract = {We study sequences of noncommutative random variables which are invariant under "quantum transformations" coming from an orthogonal quantum group satisfying the "easiness" condition axiomatized in our previous paper. For 10 easy quantum groups, we obtain de Finetti type theorems characterizing the joint distribution of any infinite quantum invariant sequence. In particular, we give a new and unified proof of the classical results of de Finetti and Freedman for the easy groups S_n, O_n, which is based on the combinatorial theory of cumulants. We also recover the free de Finetti theorem of K\"ostler and Speicher, and the characterization of operator-valued free semicircular families due to Curran. We consider also finite sequences, and prove an approximation result in the spirit of Diaconis and Freedman.}, added-at = {2020-02-06T15:17:03.000+0100}, author = {Banica, Teodor and Curran, Stephen and Speicher, Roland}, biburl = {https://www.bibsonomy.org/bibtex/2b2a42a2bc0d06e4260b531c61dee1560/kirk86}, description = {[0907.3314] De Finetti theorems for easy quantum groups}, doi = {10.1214/10-AOP619}, interhash = {245c5a90004b58643046c65199aa0e97}, intrahash = {b2a42a2bc0d06e4260b531c61dee1560}, keywords = {probability theory}, note = {cite arxiv:0907.3314Comment: Published in at http://dx.doi.org/10.1214/10-AOP619 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)}, timestamp = {2020-02-06T15:17:12.000+0100}, title = {De Finetti theorems for easy quantum groups}, url = {http://arxiv.org/abs/0907.3314}, year = 2009 }