  The degenerate Fermi gas coupled to a random potential is used to study
metal-insulator transitions in various dimensions.
  We first recast the problem in the sea-boson language that allows for an easy
evaluation of important physical attributes.
  We evaluate the dynamical number-number correlation function and from this
compute the a.c. conductivity.
  We find that the d.c. conductivity vanishes in one and two dimensions.
  For a hamiltonian that forbids scattering of an electron from within the
Fermi surface to another state within the Fermi surface we find that there is
no metal-insulator transition in three dimensions either.
