On Decidable Fragments of Theories in Field Arithmetic

碩士 === 國立交通大學 === 應用數學系所 === 106 === In this thesis, we prove the preservation theorem of ∀^n∃ sentences over number fields under existentially closedness. We show that the ∃∀ theories of Hilbertian fields with characteristic 0 and perfect Hilbertian fields are both decidable. We also prove that th...

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Bibliographic Details
Main Authors: Lin, Chun-Yu, 林俊佑
Other Authors: Tung, Shih-Ping
Format: Others
Language:en_US
Published: 2018
Online Access:http://ndltd.ncl.edu.tw/handle/pp7377
Description
Summary:碩士 === 國立交通大學 === 應用數學系所 === 106 === In this thesis, we prove the preservation theorem of ∀^n∃ sentences over number fields under existentially closedness. We show that the ∃∀ theories of Hilbertian fields with characteristic 0 and perfect Hilbertian fields are both decidable. We also prove that the ∀∃ theories of Hilbertian fields with characteristic 0, Hilbertian fields, PAC fields with characteristic 0, and PAC fields are all decidable.