Varying α in the early universe: CMB, LSS and FMA

Original · EN

I review recent constraints on and claimed detections of a time-varying fine-structure constant α, and discuss our own work, particularly on the effects of α in the cosmic microwave background and large-scale structure. Our results are consistent with no variation in α from the epoch of recombination to the present day, and restrict any such variation to be less than about 4%. The forthcoming MAP and Planck experiments will be able to break most of the currently existing degeneracies between α and other parameters, and measure α to better than percent accuracy.