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The sequential stability index of a function space

Published online by Cambridge University Press:  26 February 2010

J. M. Anderson
Affiliation:
Department of Mathematics, University College London.
J. E. Jayne
Affiliation:
Department of Mathematics, University College London.
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Extract

One of the substantial differences between real and complex analysis is the behaviour of pointwise sequential limits of functions. It is well known that, if f(z) is a bounded analytic function in D = {zC: |z| < 1}, then there exists a sequence {pn(z): n = 1,2,…} of polynomials such that

(i) ‖Pn‖ ≤ ‖f‖ for all n = 1,2,3,…, and

(ii) for each zD, Pn(Z) → f(z) as n → ∞,

where we have used the notation

Type
Research Article
Copyright
Copyright © University College London 1973

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