Cosmological singularities and modified theories of gravityLeonardoFernández JambrinaauthorRuthLazkozauthorWe consider perturbative modifications of the Friedmann equations in terms of density corresponding to modified theories of gravity proposed as an alternative route to comply with the observed accelerated expansion of the universe. Assuming that the present matter content of the universe is a pressureless fluid, the possible singularities that may arise as the final state of the universe are surveyed. It is shown that, at most, two coefficients of the perturbative expansion of the Friedman equations are relevant for the analysis. Some examples of application of the perturbative scheme are included.Physics2009American Institute of Physics (AIP)Presentation at Congress or Conference