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UPPER AND LOWER FREQUENTLY UNIVERSAL SERIES

Published online by Cambridge University Press:  25 February 2013

CHRISTOS PAPACHRISTODOULOS*
Affiliation:
Department of Mathematics, University of Crete, KNOSSOS AV. 71409Heraklion, Crete, Greece e-mail: papach@math.uoc.gr
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Abstract

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We introduce the notion of upper and lower frequently universal sequences and see that ‘most’ of the universal approximations are obtained by sets of indices which have upper density 1 and lower density 0. We also show that a class of universal series related to lower density is of first category.

Keywords

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 2013 

References

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