General regular variation, Popa groups and quantifier weakening
Ostaszewski, A.
& Bingham, N. H.
(2020).
General regular variation, Popa groups and quantifier weakening.
Journal of Mathematical Analysis and Applications,
483(2).
https://doi.org/10.1016/j.jmaa.2019.123610
& Bingham, N. H.
(2020).
General regular variation, Popa groups and quantifier weakening.
Journal of Mathematical Analysis and Applications,
483(2).
https://doi.org/10.1016/j.jmaa.2019.123610
We introduce general regular variation, a theory of regular variation containing the existing Karamata, Bojanic-Karamata/de Haan and Beurling theories as special cases. The unifying theme is the Popa groups of our title viewed as locally compact abelian ordered topological groups, together with their Haar measure and Fourier theory. The power of this unified approach is shown by the simplification it brings to the whole area of quantifier weakening, so important in this field.