UnstableK-cohomology algebra is filteredλ-ring

Unstable K-cohomology Algebra Is Filtered Λ-ring

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. 1. Introduction. Lambda operations in complex K-theory were f...

Unstable K-cohomology Algebra Is Filtered Lambda-ring

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.

The Hochschild Cohomology Ring modulo Nilpotence of a Monomial Algebra

For a finite dimensional monomial algebra Λ over a field K we show that the Hochschild cohomology ring of Λ modulo the ideal generated by homogeneous nilpotent elements is a commutative finitely generated Kalgebra of Krull dimension at most one. This was conjectured to be true for any finite dimensional algebra over a field in [13].

Tate Cohomology in Commutative Algebra.

Computing The Cubical Cohomology Ring

The goal of this work is to establish a new algorithm for computing the cohomology ring of cubical complexes. The cubical structure enables an explicit recurrence formula for the cup product. We derive this formula and, next, show how to extend the Mrozek and Batko [7] homology coreduction algorithm to the cohomology ring structure. The implementation of the algorithm is a work in progress. Thi...