Amphithéâtre Léon Motchane (Institut des Hautes Etudes Scientifiques)
Amphithéâtre Léon Motchane
Institut des Hautes Etudes Scientifiques
35, route de Chartres
I review a class of nonlocally modified gravity models which were proposed to explain the current phase of cosmic acceleration without dark energy. Among the topics considered are deriving causal and conserved field equations, adjusting the model to make it support a given expansion history, why these models do not require an elaborate screening mechanism to evade solar system tests, degrees of freedom and kinetic stability, and the negative verdict of structure formation. Although these simple models are not consistent with data on the growth of cosmic structures many of their features are likely to carry over to more complicated models which are in better agreement with the data. The talk is be based on 1401.0254.