In this paper we study
embeddings of a graph G in Euclidean space Rn that are ‘regular’ in the following
sense: given any two distinct vertices u and v of G, the distance between the
corresponding points in Rn equals α if u and v are adjacent, and equals β otherwise.
It is shown that for any given value of s = (β2−α2)∕β2, the minimum dimension of a
Euclidean space in which G is regularly embeddable is determined by the
characteristic polynomials of G and Ḡ.