A Fomin-Kirillov algebra over a field of field
characteristic zero is the associative algebra
generated by
for
with quadratic relations
|
(1)
| |||
|
(2)
| |||
|
(3)
| |||
|
(4)
|
where the middle two relations hold for and the last for pairwise distinct
,
,
, and
with
and
.
The algebras are finite-dimensional for ,
4, and 5. Andruskiewitsch et al. (2026) proved that
is infinite-dimensional for every
. Andruskiewitsch et al. (2026) credit
GPT-6 Astra with suggesting a proof strategy for the case
, which they partly adopted and partly developed within
a more general argument.