Modifying gravity at large distances by means of a massive graviton may explain the observed acceleration of the Universe without Dark Energy.
The standard paradigm for Massive Gravity is the Fierz-Pauli theory, which, nonetheless, displays well known flaws in its massless limit. The most serious one is represented by the vDVZ discontinuity, which consists in a disagreement between the massless limit of the Fierz-Pauli theory and General Relativity. A field-theoretical treatment of linearized Massive Gravity leads to an alternative theory describing the five degrees of freedom of the graviton, with a good massless limit, without vDVZ discontinuity, and depending on one mass parameter only, in agreement with the Fierz-Pauli theory.