Pisier's characterization of Sidon sets as containing proportional-sized quasi-independent subsets is given a sharper form for groups with only a finite number of elements having orders a power of 2. No such improvement is possible for a general Sidon subset of a group having an infinite number of elements of order 2. The method used also gives several sharper forms of Ramsey's characterization of Sidon sets as containing proportional-sized I₀-subsets in a uniform way, again in groups containing but a finite number of elements of order 2.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm112-2-1,
author = {Colin C. Graham and Kathryn E. Hare},
title = {Characterizing Sidon sets by interpolation properties of subsets},
journal = {Colloquium Mathematicae},
volume = {111},
year = {2008},
pages = {175-199},
zbl = {1134.42307},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm112-2-1}
}
Colin C. Graham; Kathryn E. Hare. Characterizing Sidon sets by interpolation properties of subsets. Colloquium Mathematicae, Tome 111 (2008) pp. 175-199. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm112-2-1/