Density estimates of 1-avoiding sets via higher order correlations
arXiv:1809.05453 · doi:10.1007/s00454-020-00263-3
Abstract
We improve the best known upper bound on the density of a planar measurable set A containing no two points at unit distance to 0.25442. We use a combination of Fourier analytic and linear programming methods to obtain the result. The estimate is achieved by means of obtaining new linear constraints on the autocorrelation function of A utilizing triple-order correlations in A, a concept that has not been previously studied.
11 pages, 2 figures