Skip to main content
11 events
when toggle format what by license comment
Oct 30, 2019 at 19:08 comment added Asaf Karagila Obligatory SMBC reference.
Oct 30, 2019 at 19:06 comment added Denis Nardin @AsafKaragila Take it up with whoever thought it was a good idea to call the unique complete ordered field the "real" numbers (not like those fake numbers like $i$)...
Oct 30, 2019 at 16:45 comment added Asaf Karagila The real spectrum! As opposed to the fake spectrum which appears often in the liberal, left-wing preprint suppositories!
Oct 30, 2019 at 9:56 history edited Denis Nardin CC BY-SA 4.0
added 2 characters in body
Oct 30, 2019 at 9:55 comment added YCor Reference to Harrison topology: Harrison, D. K. Finite and infinite primes for rings and fields. Mem. Amer. Math. Soc. No. 68, 1966, 62 pp.
Oct 30, 2019 at 9:53 history edited Denis Nardin CC BY-SA 4.0
added 18 characters in body
Oct 30, 2019 at 9:29 comment added Denis Nardin @HenrikRüping There is a naturally defined map from $\mathrm{Sper}\,\mathbb{Q}(x)$ to $\mathbb{P}^1(\mathbb{R})$, whose fibers are either $\{\pm 1\}$ or just a point depending if the target is algebraic or not. This can be generalized to a map from $\mathrm{Sper}\,F$ to the $\mathbb{R}$-points of the Zariski-Riemann space of $F$, and that's what you're seeing. The fiber over a point $(v,k(v)\to\mathbb{R})$ is given (noncanonically) by the set of homomorphisms from the valuation group of $v$ to $\{\pm1\}$.
Oct 30, 2019 at 9:25 comment added HenrikRüping It seems as if at least for the upper example the set of all orders is ordered itself and that there is a canonical quotient map identifying $a^\pm$ such that the quotient space is $[-\infty,\infty]$. This seems really similar to the setting where one takes the standard cantor set and identifies both endpoints of each removed interval and the quotient space is again a unit interval.
Oct 30, 2019 at 8:56 vote accept HenrikRüping
Oct 30, 2019 at 8:50 history edited Denis Nardin CC BY-SA 4.0
added 14 characters in body
Oct 30, 2019 at 8:38 history answered Denis Nardin CC BY-SA 4.0