Diagonal diophantine approximation in Q and the Duffin-Schaeffer theorem in number fields

The central aim of this thesis is to prove various Diophantine approximation results which quantify cases of the weak approximation theorem. We take finitely many different completions of a global field , take their direct product, and approximate elements of this space by elements of the global fie...

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Bibliographic Details
Main Author: Palmer, Matthew Iain
Published: University of Bristol 2016
Subjects:
512
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702165
Description
Summary:The central aim of this thesis is to prove various Diophantine approximation results which quantify cases of the weak approximation theorem. We take finitely many different completions of a global field , take their direct product, and approximate elements of this space by elements of the global field. We prove analogues of Gallagher's zero-one law, and of the Duffin-Schaeffer theorem, in two setups of this type: the direct product of finitely many completions of Q (always including R), and the direct product of all of the Archimedean completions of a general number field . The second result in particular forms a significant improvement on existing results, which were only proven for imaginary quadratic fields.