Testes observacionais da isotropia cosmologica

Abstract

In this work, we probe the validity of the cosmological isotropy hypothesis, which constitutes one of the main pillars of the Cosmological Principle, in the light of current observational data. We search for possible signatures of isotropy violation in the latest compilations of Type Ia Supernovae distance measurements, in addition to the large angle distribution of cosmic objects such as galaxies observed in the infra-red, and galaxy clusters detected via Sunyaev-Zeldovich effect. Model-independent methods are adopted to perform our analyses throughout this work, comparing them with simulations produced under the isotropy condition in order to verify possible inconsistencies that might indicate a potential violation of the cosmological isotropy. No significant suggestion for such anisotropic signal (except for local bulk flows), nevertheless, has been detected in our analyses once we account for the observational limitations and other systematics in simulated data sets. Therefore, we conclude that one of the most fundamental assumptions of the Universe presents good concordance with astrophysical observations currently available, and that we expect that future surveys may be able to underpin whether the cosmic isotropy, besides the homogeneity assumption, provide a valid (or invalid) description of the observed Universe.