{"title":"大的简单域的伽罗瓦群","authors":"Anand Pillay, Erik Walsberg","doi":"10.2140/mt.2023.2.357","DOIUrl":null,"url":null,"abstract":"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 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 PAC field L with the same absolute Galois group as K . In the appendix we show that if K is large and NSOP ∞ and v is a nontrivial 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 SOP ∞ (without assuming largeness).","PeriodicalId":21757,"journal":{"name":"Simul. Model. Pract. Theory","volume":"93 4","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Galois groups of large simple fields\",\"authors\":\"Anand Pillay, Erik Walsberg\",\"doi\":\"10.2140/mt.2023.2.357\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"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 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 PAC field L with the same absolute Galois group as K . In the appendix we show that if K is large and NSOP ∞ and v is a nontrivial 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 SOP ∞ (without assuming largeness).\",\"PeriodicalId\":21757,\"journal\":{\"name\":\"Simul. Model. Pract. Theory\",\"volume\":\"93 4\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-10-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Simul. Model. Pract. Theory\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.2140/mt.2023.2.357\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Simul. Model. Pract. Theory","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2140/mt.2023.2.357","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
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 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 PAC field L with the same absolute Galois group as K . In the appendix we show that if K is large and NSOP ∞ and v is a nontrivial 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 SOP ∞ (without assuming largeness).