  We study a zero-range process with system-size dependent jump rates, which is
known to exhibit a discontinuous condensation transition. Metastable
homogeneous phases and condensed phases coexist in extended phase regions
around the transition, which have been fully characterized in the context of
the equivalence and non-equivalence of ensembles. In this communication we
report rigorous results on the large deviation properties and the free energy
landscape which determine the metastable dynamics of the system. Within the
condensed phase region we identify a new dynamic transition line which
separates two distinct mechanism of motion of the condensate, and provide a
complete discussion of all relevant timescales. Our results are directly
related to recent interest in metastable dynamics of condensing particle
systems. Our approach applies to more general condensing particle systems,
which exhibit the dynamical transition as a finite size effect.
