standard cosmological model

This is the most precise and widespread theoretical model for explaining the history of the Universe and its behaviour. It is based on the premise that the Universe, ever since the big bang 15 billion years ago, is in isotropic expansion, and therefore it has invariable physical properties according to direction, being homogeneous on a very large scale. Certain anomalies, revealed at the edge of the Universe, in particular by the satellite Planck, but also by the study of bigger quasar structures than the model allows for, tend to demonstrate some of the limitations of this model. More and more theories cast doubt on the fact that the Universe is in isotropic expansion, and suggest that it presents different characteristics in some directions. It could be the case, for example, that it is not expanding at the same speed in all directions.