  We investigate correlations in the fragment momentum distribution due to the
propagation of fragments under the influence of their mutual Coulomb field,
after the breakup of an excited nuclear source.The magnitude of the effects on
the nuclear temperatures obtained from such distributions is estimated with the
help of a simple approach in which a charged fragment interacts with a
homogeneous charged sphere. The resuslts are used to correct the temperatures
obtained from the asymptotic momentum distributions of fragments produced by a
Monte-Carlo simulation in which the system's configuration at breakup is
provided by the canonical version of the Statistical Multifragmentation Model.
In a separate calculation, the dynamics of this many-particle charged system is
followed in a molecular dynamics calculation until the fragments are far away
from the breakup volume. The results suggest that, although the magnitude of
the corrections is similar in both models, many-particle correlations present
in the second approach are non-negligible and should be taken into account in
order to minimize ambiguities in such studies.
