  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.
Our approach is based on a field theoretical treatment of Massive Gravity:
General Relativity, in the weak field approximation, is treated as a gauge
theory of a symmetric rank-2 tensor field. This leads us to propose an
alternative theory of linearized Massive Gravity, describing 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.
