  We suggest a time-dependent dynamical mean-field-hydrodynamic model for the
collapse of a trapped boson-fermion condensate and perform numerical simulation
based on it to understand some aspects of the experiment by Modugno et al.
[Science 297, 2240 (2002)] on the collapse of the fermionic condensate in the
40K-87Rb mixture. We show that the mean-field model explains the formation of a
stationary boson-fermion condensate at zero temparature with relative sizes
compatible with experiment. This model is also found to yield a faithful
representation of the collapse dynamics in qualitative agreement with
experiment. In particular we consider the collapse of the fermionic condensate
associated with (a) an increase of the number of bosonic atoms as in the
experiment and (b) an increase of the attractive boson-fermion interaction
using a Feshbach resonance. Suggestion for experiments of fermionic collapse
using a Feshbach resonance is made.
