Are statistical notions applicable in the early universe

The description of fundamental particles by means of spontaneously broken gauge theories has been remarkably successful. A natural extension of the Weinberg-Salam theory to a grand unified theory combines the electromagnetic weak and strong interactions in an interesting and suggestive manner. Just as the Weinberg-Salam theory requires the existence of heavy Bosons of mass approx. 102 GeV, the SU(5) unified theory demands the existence of an M/sub x/ meson of mass approx. 1015 GeV. The existence of such objects would have observable, even dramatic effects at temperatures of 10150K and 10280K, respectively. Such temperatures can only be expected to exist in very unusual circumstances, such as the early epochs in the universe. It has been possible by combining the ideas of cosmology, quantum field theory and statistical mechanics to give interesting explanations of the baryon asymmetry and the absence of magnetic monopoles in the universe at the present time