Two notions of unit distance graphs

A complete (unit) distance graph in ℝo(1))dn log2 n, while the number of distance graphs in ℝd on n labelled vertices is 2(1−1/⌊d/2⌋+o>(1))n 2/2. This is used to study a Ramsey type question involving these graphs. Finally, we discuss the following problem: what is the minimum number of edges a graph must have so that it is not realizable as a complete distance graph in ℝd?