The determinant of [2], p.99 is
, since there are d-2 nonreal
conjugates, where
denotes not the discriminant of the field
, but rather the discriminant of the order
i.e.,
the discriminant of the minimal polynomial P of
. Thus, the number of points
of
in a large cube of volume V is asymptotically
.
Now, consider the iterates as points in the lattice
. By definition,
. The conjugate
of
corresponding to
is
, which satisfies
. For a typical conjugate
with
, the corresponding conjugate of
is
. However, it is reasonable to expect that
may be
for some
. In fact, it is plausible that
, as we
argue in section 6.4 below. The following result contains the only completely rigorous argument
of this section.
Suppose that, and that
for all conjugates
, for some
. Then
is a beta number (and hence
).
Remark 6.1 It is not clear how one would prove that
with
for some given
. The main virtue of Proposition 6.1 is that
it shows that there is a threshold for the rate of growth of
which must be
exceeded before nonperiodicity is possible.