Daniele Steer | Auditório Abreu Faro, Complexo Interdisciplinar
General relativity, proposed by Einstein in 1915, passes a whole array of solar system experimental tests with flying colors. But is it a good description of gravity on the very largest cosmological scales in the universe?
In this talk we use these different experimental observations to explore the possibility that general relativity is perhaps not valid on cosmological scales where it should be “modified”. We discuss different avenues to modifying gravity, and learn why modifying gravity is a difficult thing to do. After a brief overview of some of the most interesting modified gravity theories that have been proposed, we finally discuss new observational tests — for instance from gravitational waves — that constrain such theories.