Multipliers of Embedded Discs

Kenneth R. Davidson, Michael Hartz, Orr Moshe Shalit

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


We consider a number of examples of multiplier algebras on Hilbert spaces associated to discs embedded into a complex ball in order to examine the isomorphism problem for multiplier algebras on complete Nevanlinna–Pick reproducing kernel Hilbert spaces. In particular, we exhibit uncountably many discs in the ball of ℓ2 which are multiplier biholomorphic but have non-isomorphic multiplier algebras. We also show that there are closed discs in the ball of ℓ2 which are varieties, and examine their multiplier algebras. In finite balls, we provide a counterpoint to a result of Alpay, Putinar and Vinnikov by providing a proper rational biholomorphism of the disc onto a variety V in B2 such that the multiplier algebra is not all of H∞(V). We also show that the transversality property, which is one of their hypotheses, is a consequence of the smoothness that they require.

Original languageEnglish
Pages (from-to)287-321
Number of pages35
JournalComplex Analysis and Operator Theory
Issue number2
StatePublished - 1 Feb 2015


  • Embedded discs
  • Isomorphism problem
  • Multiplier algebra
  • Non-selfadjoint operator algebras
  • Reproducing kernel Hilbert spaces

ASJC Scopus subject areas

  • Computational Mathematics
  • Computational Theory and Mathematics
  • Applied Mathematics


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