Wecken Type Theorems for Periodic Points
Jerzy Jezierski
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The classical Wecken theorem claims that
any self-map $f:M\to M$ of a compact manifold of dimension $\ge 3$ is
homotopic to a map having exactly $N(f)$ fixed points where $N(f)$
denotes the Nielsen number. In 1983 Boju Jiang introduced an
algebraically computable number $NF_n(f)$ which is an estimate of the
cardinality of {\it n-periodic point set} $\{x\in M; g^n(x)=x\}$ for
each $g$ homotopic to $f$.
We prove that every self-map $f:M\to M$ of a compact PL-manifold of
dimension $\ge 3$ is homotopic to a map realizing this number
i.e. there exists a $g$ homotopic to the given map $f$ and
having exactly $NF_n(f)$ n-periodic points. In particular
(for $NF_n(f)=0$) the map $f$ is homotopic to map with no
n-periodic points iff all Nielsen numbers $N(f^k)$, for all
$k$ dividing $n$, disappear.
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