Arithmetic Properties of Sparse Subsets of
Zn
Paul Potgieter
Department of Decision Sciences
University of South Africa
P. O. Box 392
Pretoria 0003
South Africa
Abstract:
Arithmetic progressions of length three may be found in compact subsets of
the reals that satisfy certain Fourier- as well as Hausdorff-dimensional
requirements. Similar results hold in the integers under analogous
conditions, with Fourier dimension being replaced by the decay of a
discrete Fourier transform. In this paper we make this correspondence
more precise, using a well-known construction by Salem. Specifically,
we show that a subset of the integers can be mapped to a compact
subset of the continuum in a way which preserves certain dimensional
properties as well as arithmetic progressions of arbitrary length. The
higher-dimensional version of this construction is then used to show
that certain parallelogram configurations must exist in sparse subsets
of Zn satisfying appropriate density and Fourier-decay conditions.
Full version: pdf,
dvi,
ps,
latex
Received August 11 2020; revised version received August 12 2020; April 15 2021.
Published in Journal of Integer Sequences,
April 16 2021.
Return to
Journal of Integer Sequences home page