  The Sine-Gordon - equivalently, the massive Thirring - Hamiltonian is
ubiquitous in low-dimensional physics, with applications that range from cold
atom and strongly correlated systems to quantum impurities. We study here its
non-equilibrium dynamics using the quantum quench protocol - following the
system as it evolves under the Sine-Gordon Hamiltonian from initial Mott type
states with large potential barriers. By means of the Bethe Ansatz we calculate
exactly the Loschmidt amplitude, the fidelity and work distribution
characterizing these quenches for different values of the interaction strength.
Some universal features are noted as well as an interesting duality relating
quenches in different parameter regimes of the model.
