TITLE: The Universal enveloping algebra of a finite dimensional Lie algebra is Noetherian.
QUESTION [7 upvotes]: If $\mathfrak{g}$ is a finite-dimensional Lie algebra, then it is very known that the Universal enveloping algebra $U(\mathfrak{g})$ of $\mathfrak{g}$ is a Noetherian ring.
What is the simplest way to show this fact?

REPLY [6 votes]: There is a nice treatment in this book. In particular, the associated graded ring $\operatorname{gr}U(\mathfrak g)$ is shown to be a finitely generated commutative $k$-algebra, generated by at most $\dim_k\mathfrak g$ elements over $k.$ It is a basic fact that such rings are noetherian, so this implies that $U(\mathfrak g)$ is itself noetherian.