The vector space tensor product
of two group representations of a group
is also a representation of
. An element
of
acts on a basis element
by
If
is a finite group and
is a faithful representation,
then any representation is contained in
for some
. If
is a representation of
and
is a representation of
, then
is a representation of
, called the external
tensor product. The regular tensor product is a special case, with the diagonal
embedding of
in
.