Probing primordial symmetry breaking with the cosmic microwave background anisotropy

Abstract

There have been vigorous research attempts to test various modified gravity theories by using the physics of the cosmic microwave background (CMB). Meanwhile, symmetry breaking such as the Higgs mechanism is one of the most important phenomena in physics, but there has not been much research to investigate them by cosmological observations. In this article, with the CMB power spectra, we try to distinguish two different scenarios of spontaneous symmetry breaking in the primordial era of the Universe. The first model is based on a broken-symmetric theory of gravity, which was suggested by Zee in 1979. The second model is an application of Palatini formalism to the first model. Perturbation equations are computed and they show that the differences originated from the property of symmetry. Furthermore, it turns out that the two models have different features of the CMB power spectra with the same potential scale. This fact enables us to verify distinct kinds of primordial symmetry breaking with CMB physics.