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Fine Structure Constant Variation

Presentation #306.02 in the session Cosmic Microwave Background — iPoster Session.

Published onJun 29, 2022
Fine Structure Constant Variation

In some extensions of the standard model of particle physics, the values of the fundamental coupling constants could vary in space and time, as they relate to the size of extra dimensions. Some recent observations of QSO have shown a possibility of time and spatial variation of the fine structure constant, alpha. We analyzed the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) model which places a cosmological scalar field and allows the field and alpha to evolve with the expansion of the universe and a low energy string theory model (Runaway Dilaton) that allows existence of a scalar field (known as Dilaton). Extensions of the scalar field in BSBM and the runaway of the dilaton allow us to consider strong couplings and predict alpha variation across time and space that are consistent with the variation of Hubble parameters allowed by Plank. From those models, we then explore which models are allowed by QSO data by constraining free parameters and couplings. We make predictions for variations in alpha at the surface of last scattering, which could be tested using the Cosmic Microwave Background radiation. After constraining the coupling parameters in both models we find that both models allow alpha variation and a possibility of further constraining Runaway Dilaton couplings using CMB data using Marcov Chains Monte Carlo simulations and principal component analysis.

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