AMI will combine a large field of view with high sensitivity to faint objects, making it ideal for surveying the sky for the imprints of galaxy clusters on the microwave background. Optical and X-ray telescopes that search for clusters of galaxies are hampered by the fact that the clusters get fainter with increasing distance. It is therefore very difficult to find the most distant clusters that would tell us about the formation of structure in the universe.
Different theories predict hugely different numbers of distant clusters.
AMI will be able to count these clusters and thus determine which theory is correct. Simulated AMI observation of about 1 square degree of sky, with a total observing time of 360 hours. In this model, in which the total mass density of the universe is equal to the critical density, large clusters form late in the history of the universe and there are relatively few distant clusters. Identical simulation to the above, but with the density only 0.3 times the critical density. Now clusters form at earlier times and there are many distant clusters.