3
$\begingroup$

In my understanding, for a number field $K$, one can identify $K^{\times}$ with a subring of $\mathbb{A}_K$ (the adele ring), and then define the idele class group as $$0 \longrightarrow K^{\times} \longrightarrow \mathbb{A}_{K}^{\times} \longrightarrow C_K \longrightarrow 0 ,$$ Are there any conditions on $K$ that will make this exact sequence split?

Thank you

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.