Computation of the classifying ring of formal modules

Andrew Salch

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arXiv · 1511.03784

Computation of the classifying ring of formal modules

Andrew Salch

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Abstract

In this paper, we develop general machinery for computing the classifying ring $L^A$ of one-dimensional formal $A$-modules, for various commutative rings $A$. We then apply the machinery to obtain calculations of $L^A$ for various number rings and cyclic group rings $A$. This includes the first full calculations of the ring $L^A$ in cases in which it fails to be a polynomial algebra. We also derive consequences for the solvability of some lifting and extension problems.

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Andrew Salch. 2015-11-12. Computation of the classifying ring of formal modules. https://arxiv.org/abs/1511.03784

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