Abstract:
This work aims to obtain a non-parametric reconstruction of the temperature evolution law of the cosmic microwave background by the application of Gaussian Processes and to set constraints on cosmologies that violate the duality-distance relation. The constraints obtained are on the photon production rate expressed by an extra parameter in the temperature-redshift relation that quantifies a possible deviation from standard evolution. With the application of Gaussian Processes to the available data temperature profiles were reconstructed and using a statistical criteria those which were too far from the standard model prediction were discarded. Each non-parametric evolution of this photon creation rate was compared with two best-fit parametric regression models. Non-parametric reconstructions in statistical discrepancy with the parametric ones were disregarded. The chosen reconstructions were then used to calculate constraints on both the distance-duality relation and variation of the fine-structure constant. A good agreement with the predictions of the standard cosmology was found.
