Extending automorphisms over $\RR^{p+2}$ and realizing DE attractors
arXiv:0811.4032
Abstract
In this paper we consider the realization of DE attractors by self-diffeomorphisms of manifolds. For any expanding self-map of a connected, closed -dimensional manifold , one can always realize a -type attractor derived from by a compactly-supported self-diffeomorphsm of $\RR^{p+q}$, as long as . Thus lower codimensional realizations are more interesting, related to the knotting problem below the stable range. We show that for any expanding self-map of a standard smooth -dimensional torus , there is compactly-supported self-diffeomorphism of $\RR^{p+2}$ realizing an attractor derived from . A key ingredient of the construction is to understand automorphisms of which extend over $\RR^{p+2}$ as a self-diffeomorphism via the standard unknotted embedding $\imath_p:T^p\hookrightarrow\RR^{p+2}$. We show that these automorphisms form a subgroup of $\Aut(T^p)$ of index at most .
19 pages, 4 figures