A note on the unit distance problem for planar configurations with Q-independent direction set
Abstract
Let denote the maximum number of unit distances that a set of points in the Euclidean plane can determine with the additional condition that the distinct unit length directions determined by the configuration must be -independent. This is related to the Erdos unit distance problem but with a simplifying additional assumption on the direction set which holds "generically". We show that is the Hamming weight of , i.e., the number of nonzero binary coefficients in the binary expansion of , and find a formula for explicitly. In particular is . Furthermore we describe a process to construct a set of points in the plane with -independent unit length direction set which achieves exactly unit distances. In the process of doing this, we show is also the same as the maximum number of edges a subset of vertices of size determines in either the countably infinite lattice or the infinite hypercube graph . The problem of determining T(n) can be viewed as either a type of packing or isoperimetric problem.
Keywords
Cite
@article{arxiv.1406.6029,
title = {A note on the unit distance problem for planar configurations with Q-independent direction set},
author = {Mark Herman and Jonathan Pakianathan},
journal= {arXiv preprint arXiv:1406.6029},
year = {2014}
}
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19 pages