A result announced by R. F.
Brown in 1963, and completed by Brown and Fadell, generalizing classical results of
H. Hopf for differentiable manifolds, is the following:
Theorem: Let M be a compact connected topological manifold; then
(a) M admits arbitrarily small maps with a single fixed point;
(b) If the Euler characteristic χM of M is zero, then M admits arbitrarily
small maps without fixed points (and conversely). Here a map is small if it
is close to the identity map. We propose to give a short proof of this
theorem.
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