Filtration on commutative algebra

66 Views Asked by At

Given a unital associative commutative algebra $A$ with over a ring/field K, with a filtration, i.e. collection of vector subspaces $0=F_0 \subset F_1 \subset ... \subset F_n = A$ such that $F_m \cdot F_n \subset F_{m+n}$, is it true that the associated graded algebra $\mathcal{G}(A)$ is isomorphic to $A$ as an algebra? Does the answer depend on whether K is ring/field?