It is interesting to observe that it is possible to define a version of
this model in which the limit
is taken. It is possible
to show, with all mathematical rigor, and for any
and any
, that
the limit of the
polynomial model we have here, in which one
makes
and
in such a way that
is kept finite, is in fact the
non-linear Sigma Model with coupling constant
. It is therefore
possible that the
non-linear Sigma Models in
or more may
still have some interesting continuum limits.