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Unstable $K$-cohomology algebra is filtered lambda-ring

Donald Yau
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Abstract

Boardman, Johnson, and Wilson gave a precise formulation for an unstable algebra over a generalized cohomology theory. Modifying their definition slightly in the case of complex K-theory by taking into account its periodicity, we prove that an unstable algebra for complex $K$-theory is precisely a filtered $λ$-ring, and vice versa.

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Donald Yau. 2002-09-04. Unstable $K$-cohomology algebra is filtered lambda-ring. https://arxiv.org/abs/math/0209033

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