Local field invariants (reviewed)

The basic invariants of a local field $K$ are:

• the degree $d$
• the ramification index $e$
• the residue field degree $f$
• the discriminant exponent $c$
• the discriminant root field $\mathbb Q_p(\sqrt{\textrm{disc}(K)})$
• the root number $\varepsilon$
• the automorphism group $\textrm{Aut}(K/\mathbb Q_p)$