ΛCDM模型
Except in the speculative case of phantom energy (which violates all the energy conditions), all postulated forms of mass-energy yield a deceleration parameter formula_31 Thus, any non-phantom universe should have a decreasing Hubble parameter, except in the case of the distant future of a Lambda-CDM model, where formula_1 will tend to −1 from above and the Hubble parameter will asymptote to a constant value of formula_33.