2023/08/12 by Bhangale, Amey, Khot, Subhash, Minzer, Dor · 2 citations
#Combinatorics (math.CO) #Discrete Mathematics (cs.DM) #FOS: Computer and information sciences #FOS: Mathematics
paper · doi:10.48550/arxiv.2308.06600
For a prime p, a restricted arithmetic progression in \mathbbFpn is a triplet of vectors x, x+a, x+2a in which the common difference a is a non-zero element from \0,1,2\n. What is the size of the largest A⊆ \mathbbFpn that is free of restricted arithmetic progressions? We show that the density of any such a set is at most (C)/((logloglog n)c), where c,C>0 depend only on p, giving the first reasonable bounds for the density of such sets. Previously, the best known bound was O(1/log* n), which follows from the density Hales-Jewett theorem.