UM TESTE INDEPENDENTE DE MODELO DA VARIABILIDADE DA VELOCIDADE DA LUZ COM OBSERVAÇÕES COSMOLÓGICAS

Abstract

Testing the variability of fundamental constants in Nature consists in one of the strongest tests of fundamental Physics. Any significant evolution of these values would immediately hint at new physics, and demand a profound reformulation of the standard model of Cosmology and Particles, not to mention Electromagnetism, Thermodynamics and Gravitation. Such tests have been thoroughly carried out on Earth and its surrounding Solar neighborhood for decades with exquisite precision, providing no evidence for their evolution. However, cosmological tests of this kind are still sparse given the difficulty of taking precise observations at high redshifts. Hence, there is an urge to seek them as a means to challenge the validity of the standard cosmological model. In this work we perform a cosmological measurement of the speed of light using the latest Type Ia Supernova and cosmic chronometer observations at the redshift range 0<z<2. Our method relies on the numerical reconstruction of these data in order to circumvent a priori assumptions of the underlying cosmology. We confirm the constancy of the speed of light at such redshift range, reporting two ∼5% precision measurements of c=(3.20±0.16)×10^5 km/s^(-1) in z≃1,58, and c=(2.67±0.14)×10^5 km/s^(-1) in z≃1,36, depending on the reconstruction method, at a 1σ confidence level.