An example of the statistic as a function of circle radius α for a simulated CMB map (shown in Fig. 4) of a universe with the topology of a cubic 3-torus with dimensions (solid line). The dash-dotted line show the false detection level established such that fewer than 1% out of 300 Monte Carlo simulations of the CMB map, smoothed and masked in the same way as the data, would yield a false event.