  We study the statistics of the work done, the fluctuation relations and the
irreversible entropy production in a quantum many-body system subject to the
sudden quench of a control parameter. By treating the quench as a thermodynamic
transformation we show that the emergence of irreversibility in the
nonequilibrium dynamics of closed many-body quantum systems can be accurately
characterized. We demonstrate our ideas by considering a transverse quantum
Ising model that is taken out of equilibrium by the instantaneous switching of
the transverse field.
