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Let $f: C \to C$ be a smooth function and $C$ be a compact set, subset of $\mathbb{R}^n$. We assume that all the fixed points are hyperbolic. Is it true that the number of fixed points is finite or countable?

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Aware that this exposes my ignorance, could you please define a hyperbolic point? Thanks. –  Joseph O'Rourke 7 hours ago
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Hyperbolic fixed points are isolated, are they not? That implies the number in any compact set must be finite. –  Robert Israel 5 hours ago

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As @Robert Israel pointed out, by the definition of hyperbolic fixed point the number of fixed points is finite (or countable).

A natural generalization of hyperbolicity for non isolated equilibria is that of normally hyperbolic invariant manifold. Several results that are known for hyperbolic fixed points carry to normally hyperbolic invariant manifolds, in special when the invariant manifold is compact.

An excellent book about this matter - which also treats the case when the invariant manifolds is non-compact - is Normally hyperbolic invariant manifolds — the noncompact case by J. Eldering. The pre-proof version is freely available online.

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Why the hyperbolic fixed points are isolated? In case $f$ is diffeomorphism, then i think we can use Hartman-Grobman. If $f$ is not a diffeomorphism? Thanks –  user31317 1 hour ago

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