Properties of Jacobson radical

301 Views Asked by At

I'm looking for an example of ring epimorphism $\varphi:R\rightarrow S$ such that the natural homomorphism $\tilde\varphi:J(R)\rightarrow J(S)$ is not surjective, where $J(R)$ is a Jacobson radical.

1

There are 1 best solutions below

0
On BEST ANSWER

$$\varphi:Z\rightarrow Z_8; \quad \varphi(n)=\bar n $$
$J(Z)=0$. so $\varphi(J(Z))=0$ but $J(Z_8)= \langle 2 \rangle$