The strained state cosmology

This talk presents an interpretation of the cosmological constant and of the dark energy, in terms of deformation energy density of space-time. The latter is treated as an elastic medium, whose Lagrangian density is built of terms proportional to the lowest (in practice the second) order scalars associated with the strain tensor, i.e. the difference between the actual and the Euclidean metric tensors, and its first and second order derivatives. The new Einstein equations contain an additional ’source’ corresponding to the deformation energy density of space-time. Global symmetries may be induced by texture defects in the manifold. Solutions endowed with Robertson-Walker, Schwarzschild and Kerr symmetries are discussed. The difference from massive gravity theories is evidenced.