论文标题
具有简单理论的大型田野的加洛伊斯(Galois)小组(菲利普·迪特曼(Philip Dittmann)的附录)
Galois groups of large fields with simple theory (with an appendix by Philip Dittmann)
论文作者
论文摘要
假设$ k $是一个无限的领域,它很大(从流行意义上),其一阶理论很简单。我们表明$ k $是{\ em限制},即只有任何给定有限程度的可分离扩展。我们还表明,$ k $上的任何$ 0 $ curve都具有$ k $ - 点,如果$ k $是完美的,则$ k $具有微不足道的brauer group。这些结果为猜想提供了证据,表明大型简单领域是有界PAC的。将我们的结果与Lubotzky和van den Dries的定理相结合,我们表明有一个有限的$ \ mathrm {pac} $ field $ l $,与$ k $相同的绝对Galois Group。在附录中,我们表明,如果$ k $很大,而$ \ mathrm {nsop} _ \ infty $和$ v $是$ k $ the $ k $ then $(k,v)$的非客气估值,则可以分开封闭的亨氏化,因此,尤其是$(k,v)$的残基领域,$是Algebraionally Calue Group and algebraips nater Value Group divis difis difis difis difis difis divis difis difis difis difis difis divis。附录还表明,正式和正式的$ p $ - adiC字段为$ \ mathrm {sop} _ \ infty $(不假定宽敞)。
Suppose that $K$ is an infinite field which is large (in the sense of Pop) and whose first order theory is simple. We show that $K$ is {\em bounded}, namely has only finitely many separable extensions of any given finite degree. We also show that any genus $0$ curve over $K$ has a $K$-point and if $K$ is additionally perfect then $K$ has trivial Brauer group. These results give evidence towards the conjecture that large simple fields are bounded PAC. Combining our results with a theorem of Lubotzky and van den Dries we show that there is a bounded $\mathrm{PAC}$ field $L$ with the same absolute Galois group as $K$. In the appendix we show that if $K$ is large and $\mathrm{NSOP}_\infty$ and $v$ is a non-trivial valuation on $K$ then $(K,v)$ has separably closed Henselization, so in particular the residue field of $(K,v)$ is algebraically closed and the value group is divisible. The appendix also shows that formally real and formally $p$-adic fields are $\mathrm{SOP}_\infty$ (without assuming largeness).