Skip to main content
Log in

Topological automorphism groups of compact quantum groups

  • Published:
Mathematische Zeitschrift Aims and scope Submit manuscript

Abstract

We study the topological structure of the automorphism groups of compact quantum groups showing that, in parallel to a classical result due to Iwasawa, the connected component of identity of the automorphism group and of the “inner” automorphism group coincide. For compact matrix quantum groups, which can be thought of as quantum analogues of compact Lie groups, we prove that the inner automorphism group is a compact Lie group and the outer automorphism group is discrete. Applications of this to the study of group actions on compact quantum groups are highlighted. We end by providing examples of compact matrix quantum groups with infinitely-generated fusion rings, in stark contrast with the classical situation. Along the way we study the invariant theory of finite group actions on free Laurent rings and show that the rings of invariants are, in general, not finitely generated.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Almkvist, G., Dicks, W., Formanek, E.: Hilbert series of fixed free algebras and noncommutative classical invariant theory. J. Algebra 93(1), 189–214 (1985)

    Article  MathSciNet  MATH  Google Scholar 

  2. Andruskiewitsch, N., Devoto, J.: Extensions of Hopf algebras. Algebra i Analiz 7(1), 22–61 (1995)

    MathSciNet  MATH  Google Scholar 

  3. Aubrun, G., Skalski, A., Speicher, R., Franz, U.: Quantum symmetries. volume. 2189 of lecture notes in mathematics. Springer, Berlin (2017)

    Google Scholar 

  4. Avitzour, D.: Noncommutative topological dynamics. ii. Trans. Amer. Math. Soc. 282(1), 121–135 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  5. Banica, T.: Théorie des représentations du groupe quantique compact libre \({\rm O}(n)\). C. R. Acad. Sci. Paris Sér. I Math. 322(3), 241–244 (1996)

    MathSciNet  MATH  Google Scholar 

  6. Banica, T.: Le groupe quantique compact libre \({\rm U}(n)\). Comm. Math. Phys. 190(1), 143–172 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  7. Banica, T.: Symmetries of a generic coaction. Math. Ann. 314(4), 763–780 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  8. Banica, T.: Quantum automorphism groups of small metric spaces. Pacific J. Math. 219(1), 27–51 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  9. Banica, T., Patri, I.: Maximal torus theory for compact quantum groups. to appear in Illinois J. Math. (2017)

  10. Baumslag, G.: Some reflections on proving groups residually torsion-free nilpotent. I. Illinois J. Math. 54(1), 315–325 (2010)

    MathSciNet  MATH  Google Scholar 

  11. Bergman, G.M., Shelah, S.: Closed subgroups of the infinite symmetric group. Algebra Universalis 55(2–3), 137–173 (2006). Special issue dedicated to Walter Taylor

    Article  MathSciNet  MATH  Google Scholar 

  12. Bhowmick, J., Goswami, D.: Quantum group of orientation-preserving Riemannian isometries. J. Funct. Anal. 257(8), 2530–2572 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  13. Bhowmick, Jyotishman, Skalski, Adam, Soł tan, Piotr M.: Quantum group of automorphisms of a finite quantum group. J. Algebra 423, 514–537 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  14. Bichon, Julien: Quantum automorphism groups of finite graphs. Proc. Am. Math. Soc 131(3), 665–673 (2003). (electronic)

    Article  MathSciNet  MATH  Google Scholar 

  15. Dicks, W., Formanek, E.: Poincaré series and a problem of S. Montgomery. Linear Multilinear Algebra 12(1), 21–30 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  16. Dijkhuizen, M.S., Koornwinder, T.H.: CQG algebras: a direct algebraic approach to compact quantum groups. Lett. Math. Phys. 32(4), 315–330 (1994)

    Article  MathSciNet  MATH  Google Scholar 

  17. Fima, P., Mukherjee, K., Patri, I.: On compact bicrossed products. J. Noncommut. Geom. 11(4), 1521–1591 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  18. Goswami, D., Joardar, S.: Non-existence of faithful isometric action of compact quantum groups on compact, connected Riemannian manifolds. ArXiv e-prints (2013)

  19. Goswami, Debashish: Existence and examples of quantum isometry groups for a class of compact metric spaces. Adv. Math. 280, 340–359 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  20. Green, W.L.: Topological dynamics and \(C^\ast \)-algebras. Trans. Am. Math. Soc. 210, 107–121 (1975)

    MathSciNet  MATH  Google Scholar 

  21. Halmos, P.R.: On automorphisms of compact groups. Bull. Am. Math. Soc. 49, 619–624 (1943)

    Article  MathSciNet  MATH  Google Scholar 

  22. Handelman, D.: Representation rings as invariants for compact groups and limit ratio theorems for them. Int. J. Math. 4(1), 59–88 (1993)

    Article  MathSciNet  MATH  Google Scholar 

  23. Harčenko, V.K.: Algebras of invariants of free algebras. Algebra i Logika 17(4), 478–487 (1978)

    MathSciNet  Google Scholar 

  24. Iwasawa, K.: On some types of topological groups. Ann. Math. 2(50), 507–558 (1949)

    Article  MathSciNet  MATH  Google Scholar 

  25. Jaworski, W.: Strong approximate transitivity, polynomial growth, and spread out random walks on locally compact groups. Pacific J. Math. 170(2), 517–533 (1995)

    Article  MathSciNet  MATH  Google Scholar 

  26. Jaworski, Wojciech: Contraction groups, ergodicity, and distal properties of automorphisms of compact groups. Illinois J. Math. 56(4), 1023–1084 (2012)

    MathSciNet  MATH  Google Scholar 

  27. Kasprzak, Pawel, Skalski, Adam, Soltan, Piotr: The canonical central exact sequence for locally compact quantum groups. Math. Nachr. 290(8–9), 1303–1316 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  28. Kasprzak, Pawel, Soltan, Piotr M., Woronowicz, Stanisław L.: Quantum automorphism groups of finite quantum groups are classical. J. Geom. Phys. 89, 32–37 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  29. Katznelson, Yitzhak: Ergodic automorphisms of \(T^{n}\) are Bernoulli shifts. Israel J. Math. 10, 186–195 (1971)

    Article  MathSciNet  MATH  Google Scholar 

  30. Kitchens, Bruce, Schmidt, Klaus: Automorphisms of compact groups. Ergod. Theory Dyn. Syst. 9(4), 691–735 (1989)

    Article  MathSciNet  MATH  Google Scholar 

  31. Kitchens, Bruce P.: Expansive dynamics on zero-dimensional groups. Ergod. Theory Dyn. Syst. 7(2), 249–261 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  32. Lane, D.R.: Free algebras of rank two and their automorphisms. (1976). Thesis (Ph.D.)–London

  33. Magnus, Wilhelm: Beziehungen zwischen Gruppen und Idealen in einem speziellen Ring. Math. Ann. 111(1), 259–280 (1935)

    Article  MathSciNet  MATH  Google Scholar 

  34. Mukherjee, Kunal., Patri, Issan.: Automorphisms of compact quantum groups. In: To appear in Proceedings of the London Mathematical Society

  35. Natale, Sonia: Hopf algebra extensions of group algebras and Tambara-Yamagami categories. Algebras Represent. Theory 13(6), 673–691 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  36. Passi, I.B.S.: Group rings and their augmentation ideals, volume 715 of lecture notes in mathematics. Springer, Berlin (1979)

    Book  Google Scholar 

  37. Patri, I.: Normal subgroups, center and inner automorphisms of compact quantum groups. Int. J. Math. 24(9), 1350071 (2013). (37)

    Article  MathSciNet  MATH  Google Scholar 

  38. Hertz, F.R.: Stable ergodicity of certain linear automorphisms of the torus. Ann. of Math. 162(1), 65–107 (2005). (2)

    Article  MathSciNet  MATH  Google Scholar 

  39. Segal, Graeme: The representation ring of a compact lie group. Inst. Hautes Tudes Sci. Publ. Math. 34(1), 113–128 (1968)

    Article  MathSciNet  MATH  Google Scholar 

  40. Takeuchi, Mitsuhiro: Relative Hopf modules–equivalences and freeness criteria. J. Algebra 60(2), 452–471 (1979)

    Article  MathSciNet  MATH  Google Scholar 

  41. Van Daele, Alfons, Wang, Shuzhou: Universal quantum groups. Int. J. Math. 7(2), 255–263 (1996)

    Article  MathSciNet  MATH  Google Scholar 

  42. Wang, Shuzhou: Free products of compact quantum groups. Commun. Math. Phys. 167(3), 671–692 (1995)

    Article  MathSciNet  MATH  Google Scholar 

  43. Wang, Shuzhou: Tensor products and crossed products of compact quantum groups. Proc. London Math. Soc. 71(3), 695–720 (1995). (3)

    Article  MathSciNet  MATH  Google Scholar 

  44. Wang, S.: Quantum symmetry groups of finite spaces. Commun. Math. Phys. 195(1), 195–211 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  45. Woronowicz, S.L.: Compact matrix pseudogroups. Commun. Math. Phys. 111(4), 613–665 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  46. Woronowicz, S.L.: Compact quantum groups. In: Symétries quantiques (Les Houches, 1995), North-Holland, Amsterdam (1998) p 845–884

  47. Yadav, MK.: Class preserving automorphisms of finite \(p\)-groups: a survey. In: Groups St Andrews 2009 in Bath. Volume 2, volume 388 of London Math. Soc. Lecture Note Ser., Cambridge Univ. Press, Cambridge (2011) p 569–579

Download references

Acknowledgements

This work was initiated at the 7th ECM satellite conference “Compact Quantum Groups” at Greifswald, Germany and the authors are grateful to the organizers, Uwe Franz, Malte Gerhold, Adam Skalski and Moritz Weber, for the invitation. The authors would also like to thank Yuki Arano and Makoto Yamashita for interesting discussions. The first author was partially supported by NSF grant DMS-1565226. The second author is supported by a DST Inspire Faculty Fellowship. We would like to thank the anonymous referees for numerous suggestions leading to the improvement of the paper.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Alexandru Chirvasitu.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chirvasitu, A., Patri, I. Topological automorphism groups of compact quantum groups. Math. Z. 290, 577–598 (2018). https://doi.org/10.1007/s00209-017-2032-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00209-017-2032-7

Keywords

Mathematics Subject Classification

Navigation