Perhaps a trivial question: is there an example of a field $K$ and a valuation $v$ on $K$ such that the following holds:
- $K$ is not complete (with respect to the valuation topology)
- The valuation ring $A$ (corresponding to $v$) is complete.
Thanks in advance!
PS The definitions (Bourbaki, general topology) are as follows:
valuation:
map v: $K\to \Gamma \cup \{\infty\}$ where $\Gamma$ is a totally ordered abelian group such that ... (the usual properties)
valuation ring $A$ corresponding to $v$:
$A = \{x\in K: v(x)\geq 0\}\subseteq K$
After asking the question I realised the following:
So in particular, if $A$ is complete, we have
$\hat K = \text{fraction field of } \hat A = \text{fraction field of } A = K$
So I guess the answer is no.