A maximal theorem for holomorphic semigroups

1 Department of Mathematics and Statistics, Lancaster University, Lancaster LA1 4YF, 2 School of Mathematics, The University of New South Wales, NSW 2052, Australia
Let X be a closed linear subspace of the Lebesgue space Lp(
; µ) for some 1 < p <
, and let A be an invertible operator that is the generator of a bounded holomorphic semigroup Tt on X. Then for each 0 <
< 1 the maximal function supt>0 |Ttf(x)| belongs to Lp(
; µ) for each f in the domain of A
. If moreover iA generates a bounded C0-group and A has spectrum contained in (0,
), then A has a bounded H
functional calculus.
Received 15 September 2003. Revised 24 April 2004.
* Corresponding author; E-mail: g.blower{at}lancaster.ac.uk
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