Skip to main content
Log in

Invariant subspaces generated by a single function in the Polydisk

  • Published:
Mathematical Notes Aims and scope Submit manuscript

Abstract

In this study, we partially answer a question left open in Rudin’s book “Function Theory in Polydisks” on the structure of invariant subspaces of the Hardy space H 2(U n) on the polydisk U n. We completely describe all invariant subspaces generated by a single function in the polydisk. Then, using our results, we prove the unitary equivalence of this type of invariant subspace and a characterization of outer functions in H 2(U n).

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.

Similar content being viewed by others

References

  1. O. P. Agrawal, D. N. Clark, and R. G. Douglas, “Invariant subspaces in the polydisk,” Pacific J. Math. 121 (1), 1–11 (1986).

    Article  MATH  MathSciNet  Google Scholar 

  2. A. Beurling, “On two problems concerning linear transformations in Hilbert space,” Acta Math 81, 239–255 (1948).

    Article  MATH  MathSciNet  Google Scholar 

  3. C. A. Jacewicz, “A nonprincipal invariant subspace of the Hardy space on the torus,” Proc. Amer. Math. Soc. 31, 127–129 (1972).

    Article  MATH  MathSciNet  Google Scholar 

  4. V. Mandrekar, “The validity of Beurling theorems in polydisks,” Proc. Amer. Math. Soc. 103, 145–148 (1988).

    Article  MATH  MathSciNet  Google Scholar 

  5. H. Radjavi and P. Rosenthal, Invariant Subspaces, in Ergebnisse der Mathematik und ihrer Grenzgebiete (Springer-Verlag, New York–Heidelberg, 1973), Band 77.

    Google Scholar 

  6. W. Rudin, Function Theory in Polydisks (W. A. Benjamin, Inc., New York–Amsterdam 1969).

    Google Scholar 

  7. N. M. Sadikov, “Invariant subspaces in the Hardy space on a polydisk that are generated by inner functions,” Akad. Nauk Azerbaidzhan. SSR Dokl. 39 (3), 8–11 (1983) [in Russian].

    MATH  MathSciNet  Google Scholar 

  8. J. Sarkar, A. Sasane, and B. D. Wick, “Doubly commuting submodules of the Hardy module over polydisks,” Studia Math. 217 (2), 179–192 (2013).

    Article  MATH  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to B. B. Koca.

Additional information

The article was submitted by the authors for the English version of the journal.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Koca, B.B., Sadik, N. Invariant subspaces generated by a single function in the Polydisk. Math Notes 102, 193–197 (2017). https://doi.org/10.1134/S0001434617070215

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1134/S0001434617070215

Navigation