Some remarks on dark energy models

摘要

In this talk I classify dark energy models existing in the literatures into three classes. The first one is to ascribe the cosmic acceleration to modifications of general relativity at cosmological scales. The second one is due to the backreaction of perturbations, or say, the effect of inhomogeneity of the universe. The third one is some exotic component in the universe, which appears in the right hand side of Einstein's field equations. For each class I demonstrate some examples.