Dark energy as an elastic strain fluid
The origin of the accelerated expansion of the universe is still unclear and new physics is needed on cosmological scales. We propose and test a novel interpretation of dark energy as originated by an elastic strain due to a cosmic defect in an ot herwise Euclidean space-time. The strain modifies the expansion history of the universe. Th is new effective contribution tracks radiation at early times and mimics a cosmological constant at late times. The theory is tested against observations, from nucleosynthesis to the c osmic microwave background and formation and evolution of large scale structure to supernovae. Data are very well reproduced