Displaying similar documents to “Sets of integers and quasi-integers with pairwise common divisor”

The universal functorial Lefschetz invariant

Wolfgang Lück (1999)

Fundamenta Mathematicae

Similarity:

We introduce the universal functorial Lefschetz invariant for endomorphisms of finite CW-complexes in terms of Grothendieck groups of endomorphisms of finitely generated free modules. It encompasses invariants like Lefschetz number, its generalization to the Lefschetz invariant, Nielsen number and L 2 -torsion of mapping tori. We examine its behaviour under fibrations.

A cut salad of cocycles

Jon Aaronson, Mariusz Lemańczyk, Dalibor Volný (1998)

Fundamenta Mathematicae

Similarity:

We study the centraliser of locally compact group extensions of ergodic probability preserving transformations. New methods establishing ergodicity of group extensions are introduced, and new examples of squashable and non-coalescent group extensions are constructed.