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arXiv · 1105.3876

Index formulae for integral Galois modules

Alex Bartel·Bart de Smit
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Abstract

We prove very general index formulae for integral Galois modules, specifically for units in rings of integers of number fields, for higher K-groups of rings of integers, and for Mordell-Weil groups of elliptic curves over number fields. These formulae link the respective Galois module structure to other arithmetic invariants, such as class numbers, or Tamagawa numbers and Tate-Shafarevich groups. This is a generalisation of known results on units to other Galois modules and to many more Galois groups, and at the same time a unification of the approaches hitherto developed in the case of units.

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Alex Bartel, Bart de Smit. 2011-05-19. Index formulae for integral Galois modules. https://doi.org/10.1112/jlms%2Fjdt033

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