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arXiv · 0704.2578

Formal completions of Néron models for algebraic tori

Oleg Demchenko·Alexander Gurevich·Xavier Xarles
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Abstract

We calculate the formal group law which represents the completion of the Néron model of an algebraic torus over the rationals that splits in a tamely ramified abelian extension. As a tools in the proof, we define and give criterions to compute the Weil restriction of a formal group law and the analog of the fixed part of a formal group law with respect to the action of a (finite) group.

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Oleg Demchenko, Alexander Gurevich, Xavier Xarles. 2009-11-19. Formal completions of Néron models for algebraic tori. https://doi.org/10.1112/plms%2Fpdp039

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