Fundamental Constants

In 2012 we computed the precision down to which Planck satellite could measure deviations from the adiabatic evolution of the Universe. We have used N-body simulations of thermal Sunyaev-Zeldovich effect (tSZ) to test our pipelines and our statistical estimators that were based (a) on taking the ratio of temperature anisotropies at two different frequencies; (b) fitting to the spectral variation of the cluster signal with frequency. The method (a) is very sensitive to the CMB residuals present in the data, while method (b) is not. These techniques have been applied to the CMB temperature anisotropies maps released by the Planck satellite on 2013 [1, 2].

In 2016, we investigated models allowing for a spatial variation of the fine structure constant over the sky. The main reason was that it was found a dipole modulation of the fine structure constant using spectroscopic measurements of Quasars. It was proposed an improved methodology to constrain spatial variations of the fine structure constant using clusters of galaxies and the Planck 2013 data. we fitted three different phenomenological parametrizations allowing for monopole and dipole amplitudes in the value of the fine structure constant [3].

Bibliography:

1. I. de Martino, F. Atrio-Barandela, A. da Silva, H. Ebeling, A. Kashlinsky, D. Kocevski, Carlos J.A.P. Martins, ’Measuring the redshift dependence of the CMB monopole temperature with PLANCK data. ’, 2012, Astrophys. J., 757, 144.

2. I. de Martino, R. Génova-Santos, F. Atrio-Barandela, H. Ebeling, A. Kashlinsky, D. Kocevski, Carlos J.A.P. Martins ’Constraining the redshift evolution of the cosmic microwave background black-body temperature with Planck data.’, 2015, Astrophys. J., 808, 128.

3. I. de Martino, Carlos J.A.P. Martins, H. Ebeling, D. Kocevski, ’Constraining the spatial variation of the fine structure constant using clusters of galaxies and Planck data’ , 2016, Phys. Rev. D, 94, 083008.