Result: A Szemerédi-type regularity lemma in abelian groups, with applications
1016-443X
https://zbmath.org/2228645
https://doi.org/10.1007/s00039-005-0509-8
https://www.arxiv-vanity.com/papers/math/0310476/
https://arxiv.org/pdf/math/0310476
https://link.springer.com/article/10.1007%2Fs00039-005-0509-8
https://research-information.bris.ac.uk/en/publications/a-szemeredi-type-regularity-lemma-in-abelian-groups-with-applicat
https://ora.ox.ac.uk/objects/uuid:81fa597c-50ac-4eba-931c-7f2d1c02720f
arXiv Non-Exclusive Distribution
Further Information
Szemeredi's regularity lemma is an important tool in graph theory which has applications throughout combinatorics. In this paper we prove an analogue of Szemeredi's regularity lemma in the context of abelian groups and use it to derive some results in additive number theory. One is a structure theorm for sets which are almost sum-free. If A is a subset of [N] which contains just o(N^2) triples (x,y,z) such that x + y = z then A may be written as the union of B and C, where B is sum-free and |C| = o(N). Another answers a question of Bergelson, Host and Kra. If alpha, epsilon > 0, if N > N_0(alpha,epsilon) and if A is a subset of {1,...,N} of size alpha N, then there is some non-zero d such that A contains at least (alpha^3 - epsilon)N three-term arithmetic progressions with common difference d.
31 pages. New version has an extra section and some remarks reflecting recent developments