Published online by Cambridge University Press: 23 September 2024
For a class of robustly transitive diffeomorphisms on  ${\mathbb T}^4$ introduced by Shub [Topologically transitive diffeomorphisms of
${\mathbb T}^4$ introduced by Shub [Topologically transitive diffeomorphisms of  $T^4$. Proceedings of the Symposium on Differential Equations and Dynamical Systems (Lecture notes in Mathematics, 206). Ed. D. Chillingworth. Springer, Berlin, 1971, pp. 39–40], satisfying an additional bunching condition, we show that there exists a
$T^4$. Proceedings of the Symposium on Differential Equations and Dynamical Systems (Lecture notes in Mathematics, 206). Ed. D. Chillingworth. Springer, Berlin, 1971, pp. 39–40], satisfying an additional bunching condition, we show that there exists a  $C^2$ open and
$C^2$ open and  $C^r$ dense subset
$C^r$ dense subset  ${\mathcal U}^r$,
${\mathcal U}^r$,  $2\leq r\leq \infty $, such that any two hyperbolic points of
$2\leq r\leq \infty $, such that any two hyperbolic points of  $g\in {\mathcal U}^r$ with stable index
$g\in {\mathcal U}^r$ with stable index  $2$ are homoclinically related. As a consequence, every
$2$ are homoclinically related. As a consequence, every  $g\in {\mathcal U}^r$ admits a unique homoclinic class associated to the hyperbolic periodic points with index
$g\in {\mathcal U}^r$ admits a unique homoclinic class associated to the hyperbolic periodic points with index  $2$, and this homoclinic class coincides with the whole ambient manifold. Moreover, every
$2$, and this homoclinic class coincides with the whole ambient manifold. Moreover, every  $g\in {\mathcal U}^r$ admits at most one measure of maximal entropy, and every
$g\in {\mathcal U}^r$ admits at most one measure of maximal entropy, and every  $g\in {\mathcal U}^{\infty }$ admits a unique measure of maximal entropy.
$g\in {\mathcal U}^{\infty }$ admits a unique measure of maximal entropy.
 $u$
-gibbs measures for hyperbolic skew products on
$u$
-gibbs measures for hyperbolic skew products on 
 ${T}^4$
. 2023.CrossRefGoogle Scholar
${T}^4$
. 2023.CrossRefGoogle Scholar ${T}^4$
. Proceedings of the Symposium on Differential Equations and Dynamical Systems (Lecture Notes in Mathematics, 206). Ed. Chillingworth, D.. Springer, Berlin, 1971, pp. 39–40.CrossRefGoogle Scholar
${T}^4$
. Proceedings of the Symposium on Differential Equations and Dynamical Systems (Lecture Notes in Mathematics, 206). Ed. Chillingworth, D.. Springer, Berlin, 1971, pp. 39–40.CrossRefGoogle Scholar