ArticleOriginal scientific text

Title

Generalized Lefschetz numbers of pushout maps defined on non-connected spaces

Authors 1

Affiliations

  1. Dipartimento di Matematica, Università di Milano, Via Saldini 50, 20133 Milano, Italy

Abstract

Let A, X1 and X2 be topological spaces and let i1:AX1, i2:AX2 be continuous maps. For all self-maps fA:AA, f1:X1X1 and f2:X2X2 such that f1i1=i1fA and f2i2=i2fA there exists a pushout map f defined on the pushout space X1AX2. In [F] we proved a formula relating the generalized Lefschetz numbers of f, fA, f1 and f2. We had to assume all the spaces involved were connected because in the original definition of the generalized Lefschetz number given by Husseini in [H] the space was assumed to be connected. So, to extend the result of [F] to the not necessarily connected case, a definition of generalized Lefschetz number for a map defined on a not necessarily connected space is given; it reduces to the original one when the space is connected and it is still a trace-like quantity. It allows us to prove the pushout formula in this more general case and therefore to get a tool for computing Nielsen and generalized Lefschetz numbers in a wide class of spaces.

Bibliography

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Pages:
117-135
Main language of publication
English
Published
1999
Exact and natural sciences