TITLE: Virtual Motives Infinitely Divisible by Lefschetz Motive
QUESTION [6 upvotes]: Let $K_0(Var_k)$ be the grothendieck group of the category of $k$-varieties, and call its elements virtual motives. $\mathbb{L}:=[\mathbb{A}^1_k]$ is called the Lefschetz motive. I think that if a virtual motive is divisible by arbitrarily high powers of $\mathbb{L}$, then it must be $0$. Is this true? If so, is there a proof of this?

REPLY [6 votes]: This is an open problem. It's probably quite hard.