The Expected Size of the Sphere-of-influence Graph

Abstract The sphere-of-influence graph of a set of point sites in R d is constructed by identifying the nearest neighbor of each site, centering a ball at each site so that its nearest neighbor lies on the boundary, and joining two sites by an edge if and only if their balls intersect. The asymptotic behavior of the expected number of edges of this graph is investigated when the sites are independent and uniformly distributed and their number grows without bound.