Аннотация:
An equigenerated monomial ideal
$I$
in the polynomial ring
$R=k[z_1,\ldots, z_n]$
is a
Freiman ideal if
$\mu(I^2)=\ell(I)\mu(I)-{\ell(I)\choose 2}$,
where
$\ell(I)$
is the
analytic spread of
$I$
and
$\mu(I)$
is the number of minimal the generators of
$I$.
In this
paper we classify all simple connected unmixed bipartite graphs whose cover ideals are
Freiman ideals.