Nature (ISSN 0028-0836), vol. 357, no. 6380, June 25, 1992, p. 660-665.
Watson, R. A.; Gutierrez de La Cruz, C. M.; Davies, R. D.; Lasenby, A. N.; Rebolo, R.; Beckman, J. E.; Hancock, S.
Galaxy formation by gravitational instability implies the presence of temperature fluctuations in the cosmic microwave background. New observations at 10.45 and 14.9 GHz from the Observatorio del Teide in Tenerife on angular scales of several degrees reveal structure of galactic origin at the lower frequency, while at the upper frequency the magnitude of fluctuations of cosmological origin must be less than 1.8 x 10 exp -5 on a scale of 5 deg. This strongly constrains models of galaxy formation, and is compatible with the recently announced discovery by the COBE satellite of fluctuations on larger angular scales.