$\phi: M_2(\mathbb{Z})\to \mathbb{Z}$ is necessarily trivial
55900
Is there a ring homomorphism $M_2(\mathbb Z)\to \mathbb Z$?
52081
Why is not the ring $\mathbb{Z}[2\sqrt{2}]$ a unique factorization domain?
125604
Proof that $\mathbb{Z}$ has no zero divisors
51687
Is the set $ \ (\mathbb{Z}_p \setminus \mathbb{Z}) \cap \mathbb{Q}$ non-empty?
50172
Show that $\mathbb{Q}(\sqrt{2})$ is the smallest subfield of $\mathbb{C}$ that contains $\sqrt{2}$
1020
Proving that $\mathbb{Z}[\sqrt{2}]$ is a Euclidean domain
86807
The units of $\mathbb Z[\sqrt{2}]$
122932
When $(\mathbb{Q}(\zeta_n) : \mathbb{Q}) = 2$?
7938
Number of Homomorphisms from $\Bbb{Z}_m$ to $\Bbb{Z}_n$
26661
Ring homomorphisms from $\mathbb{Z}_n$ to $\mathbb{Z}_m$
2153
How to get a homomorphism from $\mathbb{Z}\to G$, for $G$ a non-trivial group?
4530
For which natural numbers are $\phi(n)=2$?
75970
$\mathbb Z[1/2]$ is not finitely generated?
26749
$\mathbb{Z}[X]/(X^2-1)$ is not isomorphic with $\mathbb{Z}\times \mathbb{Z}$
1026
Ring homomorphism with $\phi(1_R) \neq1_S$
26233
$[K(\zeta_n):K]=\phi(n)$?
23879
If $m$ and $n$ are distinct positive integers, then $m\mathbb{Z}$ is not ring-isomorphic to $n\mathbb{Z}$