For which commutative rings k is the following true:
A k-algebra $A$ that is flat over $k$ and derived equivalent to a $k$-algebra $B$ implies that also $B$ is flat over $k$.
For which commutative rings k is the following true:
A k-algebra $A$ that is flat over $k$ and derived equivalent to a $k$-algebra $B$ implies that also $B$ is flat over $k$.