  Using operator algebraic methods we show that the moment generating function
of charge transport in a system with infinitely many non-interacting Fermions
is given by a determinant of a certain operator in the one-particle Hilbert
space. The formula is equivalent to a formula of Levitov and Lesovik in the
finite dimensional case and may be viewed as its regularized form in general.
Our result embodies two tenets often realized in mesoscopic physics, namely,
that the transport properties are essentially independent of the length of the
leads and of the depth of the Fermi sea.
