International Journal of Mathematics and Mathematical Sciences 
Volume 2003 (2003), Issue 10, Pages 593-605
doi:10.1155/S0161171203208012

Unstable K-cohomology algebra is filtered λ-ring

Donald Yau

 Department of Mathematics, University of Illinois at Urbana-Champaign, 1409 W. Green Street, Urbana 61801, IL, USA
Received 3 August 2002

Abstract

Boardman, Johnson, and Wilson (1995) 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.