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Automatic continuity via analytic thinning
Author(s):
N.
H.
Bingham;
A.
J.
Ostaszewski
Journal:
Proc. Amer. Math. Soc.
MSC (2000):
Primary 26A03
Posted:
November 5, 2009
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Abstract:
We use Choquet's analytic capacitability theorem and the Kestelman-Borwein-Ditor theorem (on the inclusion of null sequences by translation) to derive results on `analytic automaticity' - for instance, a stronger common generalization of the Jones/Kominek theorems that an additive function whose restriction is continuous/bounded on an analytic set spanning (e.g., containing a Hamel basis) is continuous on . We obtain results on `compact spannability' - the ability of compact sets to span . From this, we derive Jones' Theorem from Kominek's. We cite several applications, including the Uniform Convergence Theorem of regular variation.
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Additional Information:
N.
H.
Bingham
Affiliation:
Department of Mathematics, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
Email:
n.bingham@ic.ac.uk
A.
J.
Ostaszewski
Affiliation:
Department of Mathematics, London School of Economics, Houghton Street, London WC2A 2AE, United Kingdom
Email:
a.j.ostaszewski@lse.ac.uk
DOI:
10.1090/S0002-9939-09-09984-5
PII:
S 0002-9939(09)09984-5
Keywords:
Jones' theorem,
Kominek's theorem,
analytic set,
Choquet capacity,
Hamel basis,
uniform convergence theorem,
regular variation,
automatic continuity
Received by editor(s):
June 28, 2008,
Received by editor(s) in revised form:
April 3, 2009
Posted:
November 5, 2009
Dedicated:
To Roy Davies on the occasion of his 80th birthday
Communicated by:
Michael T. Lacey
Copyright of article:
Copyright
2009,
American Mathematical Society
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