Abstract
It is known that the structure of invariant subspaces of the Hardy space \(H^{2}({{{\mathbb {D}}}}^n)\) on the polydisc \({{\mathbb {D}}}^n\) is very complicated; hence, we need good examples help us to understand the structure of invariant subspaces of \(H^2({{\mathbb {D}}}^n)\). In this paper, we define two types of invariant subspaces of \(H^2({{\mathbb {D}}}^n)\). Then, we give a characterization of these types invariant subspaces in view of the Beurling–Lax–Halmos Theorem. Unitary equivalence is also studied in this paper.
Similar content being viewed by others
References
Agrawal, O.P., Clark, D.N., Douglas, R.G.: Invariant subspaces in the polydisk. Pac. J. Math. 121(1), 1–11 (1986)
Beurling, A.: On two problems concerning linear transformations in Hilbert space. Acta Math. 81, 17 (1948)
Chattopadhyay, A., Das, B.K., Sarkar, J.: Inner multipliers and Rudin type invariant subspaces arXiv:1503.02384 (2015)
Izuchi, K., Nakazi, T., Seto, M.: Backward shift invariant subspaces in the bidisc II. J. Oper. Theory 51, 361–376 (2004)
Jacewicz, C.A.: A nonprincipal invariant subspace of the Hardy space on the torus. Proc. Am. Math. Soc. 31, 127–129 (1972)
Koca, B.B., Sadik, N.: Invariant subspaces generated by a single function in the polydisc, arXiv:1603.01988
Nagy, B.S., Foias, C.: Harmonic Analysis of Operators on Hilbert Space. Akademiai Kiad, Budapest (1970)
Qin, Y., Yang, R.: A characterization of submodules via the Beurling–Lax–Halmos theorem. Proc. Am. Math. Soc. 142(10), 3505–3510 (2014)
Rudin, W.: Function Theory in Polydiscs. W. A. Benjamin Inc, New York (1969)
Seto, M.: Infinite sequences of inner functions and submodules in \(H^2 (D^2 )\). J. Oper. Theory 61(1), 75–86 (2009)
Seto, M., Yang, R.: Inner sequence based invariant subspaces in \(H^2 (D^2 )\). Proc. Am. Math. Soc. 135(8), 2519–2526 (2007). (electronic)
Yang, R.: Hilbert–Schmidt submodules and issues of unitary equivalence. J. Oper. Theory 53(1), 169184 (2005)
Yang, Y.: Two inner sequences based invariant subspaces in \(H^2 (D^2 )\). Integral Equ. Oper. Theory 77(2), 279–290 (2013)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Koca, B.B. Two Types of Invariant Subspaces in the Polydisc. Results Math 71, 1297–1305 (2017). https://doi.org/10.1007/s00025-016-0645-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00025-016-0645-5