Find all ideals $\mathbb{Z}[x,y]$ such that the corresponding factor ring is a UFD

151 Views Asked by At

I'm working on the following problem in Ring Theory:

$\mathbb{Z}[x,y]/\left<y+1\right>$ is a UFD.

This made me wonder if it is possible to classify all ideals $I$ in $\mathbb{Z}[x,y]$ such that $\mathbb{Z}[x,y]/I$ is a UFD?

1

There are 1 best solutions below

1
On BEST ANSWER

This is an open problem. For example, one of the most famous problems in algebraic number theory is to identify the following set: $$\{ n \in \Bbb{N} : \Bbb{Z}[x] / \langle x^2- n \rangle \mbox{ is a UFD } \}$$ it is not even known whether this set is finite or infinite.

This means that your question is already very hard for the ring $\Bbb{Z}[x]$: much harder for $\Bbb{Z}[x,y]$.