Tensor products of complementary series of rank one Lie groups
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Abstract
We consider the tensor product πα ⊗ πβ of complementary series representations πα and πβ of classical rank one groups SO 0(n; 1), SU(n; 1) and Sp(n; 1). We prove that there is a discrete component πα+β for small parameters α and β (in our parametrization). We prove further that for SO0(n; 1) there are finitely many complementary series of the form πα+β+2j , j = 0, 1,..., k, appearing in the tensor product πα ⊗ πβ of two complementary series πα and πβ where k = k(α, β n) depends on α, β and n.
Keywords
semisimple Lie groups unitary representations tensor products complementary series intertwining operatorsMSC(2010)
22E45 43A80 43A85Preview
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Notes
Acknowledgements
This work was supported by the Swedish Science Council (VR). The author dedicates this article to the memory of Professor Minde Cheng. The author met Cheng first time in the autumn of 1988 in Peking University, when he was then a graduate student in Fudan University with Professor Shaozong Yan, and Professor Lizhong Peng arranged him a visit to Peking University for 7–8 weeks. Yan had a great respect to Cheng; Yan instructed the author that this would be a very good chance to learn some hard classical harmonic analysis in Peking University, and he commissioned the author to hand over his personal letter to Cheng. In Peking University, the author attended the Harmonic Analysis Seminars there, with Professors Minde Cheng, Donggao Deng, Ruiling Long and Lizhong Peng and their graduate students. He was overwhelmed by the academic rigor and intensive research activities there. He did a talk on his work on Hankel operators, and to his surprise they asked him to give a second talk to present all technical details; their emphasis on details struck him. The author has benefited tremendously of the interaction with the harmonic analysis group in Peking University during the years to come, in particular with Peng. He takes this opportunity to thank them all, for their inspiration, encouragement, sharing their knowledge and practical material help. He thanks Jean-Louis Clerc for some stimulating discussions and careful reading of an earlier version of this paper, and Yurii Neretin for explaining some results in [20,21]. Thanks are also due to the referees for expert comments and criticisms.
References
- 1.Asmuth C, Repka J. Tensor products for SL 2(K), I: Complementary series and the special representation. Pacific J Math, 1981, 97: 271–282CrossRefMATHMathSciNetGoogle Scholar
- 2.Ben Saïd S, Koufany K, Zhang G. Invariant trilinear forms on spherical principal series of real-rank one semisimple Lie groups. Internat J Math, 2014, 25: 1450017CrossRefMATHMathSciNetGoogle Scholar
- 3.Burger M, Li J-S, Sarnak P. Ramanujan duals and automorphic spectrum. Bull Amer Math Soc (NS), 1992, 26: 253–257CrossRefMATHMathSciNetGoogle Scholar
- 4.Clerc J-L. Singular conformally invariant trilinear forms and covariant differential operators on the sphere. ArXiv: 1102.1861, 2011Google Scholar
- 5.Clerc J-L, Beckmann R. Singular conformally invariant trilinear forms and generalized Rankin-Cohen operators. ArXiv: 1104.3461, 2011Google Scholar
- 6.Clerc J-L, Kobayashi T, Ørsted B, et al. Generalized Bernstein-Reznikov integrals. Math Ann, 2011, 349: 395–431CrossRefMATHMathSciNetGoogle Scholar
- 7.Clerc J-L, Ørsted B. Conformally invariant trilinear forms on the sphere. ArXiv:1001.2851, 2010MATHGoogle Scholar
- 8.Clozel L. Spectral theory of automorphic forms. In: Automorphic Forms and Applications. IAS/Park City Mathematics Series, vol. 12. Providence: Amer Math Soc, 2007, 43–93Google Scholar
- 9.Connes A, Moscovici H. Rankin-Cohen brackets and the Hopf algebra of transverse geometry. Mosc Math J, 2004, 4: 111–130MATHMathSciNetGoogle Scholar
- 10.Cowling M, Dooley A, Korányi A, et al. An approach to symmetric spaces of rank one via groups of Heisenberg type. J Geom Anal, 1998, 8: 199–237CrossRefMATHMathSciNetGoogle Scholar
- 11.Dijk G V, Hille S C. Canonical representations related to hyperbolic spaces. J Funct Anal, 1997, 147: 109–139CrossRefMATHMathSciNetGoogle Scholar
- 12.Faraut J, Koranyi A. Function spaces and reproducing kernels on bounded symmetric domains. J Funct Anal, 1990, 88: 64–89CrossRefMATHMathSciNetGoogle Scholar
- 13.Helgason S. Groups and Geometric Analysis. London-New York: Academic Press, 1984MATHGoogle Scholar
- 14.Johnson K D, Wallach N R. Composition series and intertwining operators for the spherical principal series. I. Trans Amer Math Soc, 1977, 229: 137–173CrossRefMATHMathSciNetGoogle Scholar
- 15.Knapp A. Representation Theory of Semisimple Groups. Princeton: Princeton University Press, 1986CrossRefMATHGoogle Scholar
- 16.Kobayashi T, Pevzner M. Rankin-Cohen operators for symmetric pairs. ArXiv:1301.2111, 2013MATHGoogle Scholar
- 17.Molchanov V F. Canonical representations and overgroups. In: Lie groups and symmetric spaces. Advances in the Mathematical Sciences, vol. 54. Providence: Amer Math Soc, 2003, 213–224Google Scholar
- 18.Möllers J, Oshima Y. Restriction of most degenerate representations of O(1;N) with respect to symmetric pairs. J Math Sci Univ Tokyo, 2015, 22: 279–338MATHMathSciNetGoogle Scholar
- 19.Naimark M A. Decomposition of a tensor product of irreducible representations of the proper Lorentz group into irreducible representations. III. Tr Mosk Mat Obs, 1961, 10: 181–216MathSciNetGoogle Scholar
- 20.Neretin Y A. Plancherel formula for Berezin deformation of L 2 on Riemannian symmetric space. J Funct Anal, 2002, 189: 336–408CrossRefMATHMathSciNetGoogle Scholar
- 21.Neretin Y A, Ol′shanskii G I. Boundary values of holomorphic functions, singular unitary representations of the groups O(p; q) and their limits as q → ∞. J Math Sci (NY), 1997, 87: 3983–4035CrossRefMathSciNetGoogle Scholar
- 22.Ovsienko V, Redou P. Generalized transvectants-Rankin-Cohen brackets. Lett Math Phys, 2003, 63: 19–28CrossRefMATHMathSciNetGoogle Scholar
- 23.Peng L, Zhang G. Tensor products of holomorphic representations and bilinear differential operators. J Funct Anal, 2004, 210: 171–192CrossRefMATHMathSciNetGoogle Scholar
- 24.Pukánszky L. On the Kronecker products of irreducible representations of the 2 × 2 real unimodular group. I. Trans Amer Math Soc, 1961, 100: 116–152CrossRefMATHMathSciNetGoogle Scholar
- 25.Repka J. Tensor products of unitary representations of SL 2(R). Amer J Math, 1978, 100: 930–932CrossRefMATHMathSciNetGoogle Scholar
- 26.Repka J. Tensor products of holomorphic discrete series representations. Canada J Math, 1979, 31: 836–844CrossRefMATHMathSciNetGoogle Scholar
- 27.Speh B, Venkataramana T N. Discrete components of some complementary series representations. Indian J Pure Appl Math, 2010, 41: 145–151CrossRefMATHMathSciNetGoogle Scholar
- 28.Speh B, Zhang G. Restriction to symmetric subgroups of unitary representations of rank one semisimple Lie groups. Math Z, 2016, 283: 629–647CrossRefMATHMathSciNetGoogle Scholar
- 29.Vogan D A, Wallach N R. Intertwining operators for real reductive groups. Adv Math, 1990, 82: 203–243CrossRefMATHMathSciNetGoogle Scholar
- 30.Zhang G. Discrete components in restriction of unitary representations of rank one semisimple Lie groups. J Funct Anal, 2015, 269: 3689–3713CrossRefMATHMathSciNetGoogle Scholar