Trace formulas and dynamical zeta functions in the Nielsen theory

Abstract

In this paper we prove the trace formulas for the Reidemeister numbers of group endomorphisms in the following cases:the group is finitely generated and an endomorphism is eventually commutative; the group is finite ; the group is a direct sum of a finite group and a finitely generated free abelian group; the group is finitely generated, nilpotent and torsion free . These results had previously been known only for the finitely generated free abelian group.As a consequence, we obtain under the same conditions on the fundamental group of a compact polyhedron,the trace formulas for the Reidemeister numbers of a continuous map and under suitable conditions the trace formulas for the Nielsen numbers of a continuous map.The trace formula for the Reidemeister numbers implies the rationality of the Reidemeister zeta function. We prove the rationality and functional equation for the Reidemeister zeta function of an endomorphisms of finitely generated torsion free nilpotent group and of a direct sum of a finite group and a finitely generated free abelian group.We give a new proof of the rationality of the Reidemeister zeta function in the case when the group is finitely generated and the endomorphism is eventually commutative and in the case when group is finite.We give also another proof for the positivity of the radius of convergence of the Nielsen zeta function and propose an exast algebraic lower bound estimation for the radius.We connect the Reidemeister zeta function of an endomorphism of a direct sum of a finite group and a finitely generated free abelian group with the Lefschetz zeta function of the unitary dual map,and as consequence obtain a connection of the Reidemeister zeta function with Reidemeister torsion.