  We investigate the role played by fast quenching on the decay of metastable
(or false vacuum) states. Instead of the exponentially-slow decay rate per unit
volume, $\Gamma_{\rm HN} \sim \exp[-E_b/k_BT]$ ($E_b$ is the free energy of the
critical bubble), predicted by Homogeneous Nucleation theory, we show that
under fast enough quenching the decay rate is a power law $\Gamma_{\rm RN} \sim
[E_b/k_BT]^{-B}$, where $B$ is weakly sensitive to the temperature. For a range
of parameters, large-amplitude oscillations about the metastable state trigger
the resonant emergence of coherent subcritical configurations. Decay mechanisms
for different $E_b$ are proposed and illustrated in a (2+1)-dimensional scalar
field model.
