This issuePrevious ArticleGrowth gap versus smoothness for diffeomorphisms of the intervalNext ArticleOn the spectrum of geometric operators on Kähler manifolds
Smooth conjugacy of Anosov diffeomorphisms on higher-dimensional tori
Let $L$ be a hyperbolic automorphism of $\mathbb T^d$, $d\ge3$. We
study the smooth conjugacy problem in a small $C^1$-neighborhood
$\mathcal U$ of $L$.
The main result establishes $C^{1+\nu}$ regularity of the conjugacy
between two Anosov systems with the same periodic eigenvalue data.
We assume that these systems are $C^1$-close to an irreducible
linear hyperbolic automorphism $L$ with simple real spectrum and
that they satisfy a natural transitivity assumption on certain
intermediate foliations.
We elaborate on the example of de la Llave of two Anosov systems on
$\mathbb T^4$ with the same constant periodic eigenvalue data that
are only Hölder conjugate. We show that these examples exhaust all
possible ways to perturb a $C^{1+\nu}$ conjugacy class without
changing any periodic eigenvalue data. Also we generalize these examples
to majority of reducible toral automorphisms as well as to certain
product diffeomorphisms of $\mathbb T^4$ $C^1$-close to the original
example.