Cosmographic reconstruction of f(T) cosmology

A cosmographic reconstruction of f(T) models is here revised in a model independent way by fixing observational bounds on the most relevant terms of the f(T) Taylor expansion. We relate the f(T) models and their derivatives to the cosmographic parameters and then adopt a Monte Carlo analysis. The experimental bounds are thus independent of the choice of a particular f(T) model. The advantage of such an analysis lies on constraining the dynamics of the Universe by reconstructing the form of f(T), without any further assumptions apart from the validity of the cosmological principle and the analyticity of the f(T) function. The main result is to fix model independent cosmographic constraints on the functional form of f(T) which is compatible with the theoretical predictions. Furthermore, we infer a phenomenological expression for f(T), compatible with the current cosmographic bounds and show that small deviations are expected from a constant f(T) term, indicating that the equation of state of dark energy could slightly evolve from the one of the Lambda cold dark model. DOI: 10.1103/PhysRevD.87.064025