Cosmological tests of theories of varying fine-structure constant.

In some extensions of the standard model of particle physics, the values of the fundamental coupling constants actually vary in space and time. Some recent observations of QSO hint at the possible time and spatial variation of the fine structure constant. We analyzed the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) model which posits the existence of a cosmological scalar field and allows the field and the fine structure constant to evolve with the expansion of the universe. Using Principal Component Analysis of the CMB, we impose new constraints to these models. We also explore the relationship between the matter density and electromagnetic energy of the nucleus in these models, a key theoretical quantity that is degenerate with limits to the energy scale of new physics in these models, highlighting assumptions and limitations of past analyses. We assess the impact of the use of energy non-conserving equations in past modeling of this theory, and also explore the additional impact of dark energy constraints on such models.