Centralizers of C^1-generic diffeomorphisms

Trivial centralizers for Axiom A diffeomorphisms

We show there is a residual set of non-Anosov $C^{\infty}$ Axiom A diffeomorphisms with the no cycles property whose elements have trivial centralizer. If $M$ is a surface and $2\leq r\leq \infty$, then we will show there exists an open and dense set of of $C^r$ Axiom A diffeomorphisms with the no cycles property whose elements have trivial centralizer. Additionally, we examine commuting diffeomorphisms preserving a compact invariant set $Λ$ where $Λ$ is a hyperbolic chain recurrent class for one of the diffeomorphisms.

C1-generic conservative diffeomorphisms have trivial centralizer

We prove that the spaces of C1 symplectomorphisms and of C1 volume-preserving diffeomorphisms of connected manifolds both contain residual subsets of diffeomorphisms whose centralizers are trivial. (Les difféomorphismes conservatifs C1-génériques ont un centralisateur trivial. Nous montrons que l'espace des symplectomorphismes de classe C1 et l'espace des difféomomorphismes de classe C1 préservant une forme volume contiennent tous deux des sous-ensembles résiduels de difféomorphismes dont le centralisateur est trivial.)

Centralizers of partially hyperbolic diffeomorphisms in dimension 3

In this note we describe centralizers of volume preserving partially hyperbolic diffeomorphisms which are homotopic to identity on Seifert fibered and hyperbolic 3-manifolds. Our proof follows the strategy of Damjanovic, Wilkinson and Xu (arXiv:1902.05201) who recently classified the centralizer for perturbations of time-$1$ maps of geodesic flows in negative curvature. We strongly rely on recent classification results in dimension 3 established in (arXiv:1908.06227).

The centralizer of $C^r$-generic diffeomorphisms at hyperbolic basic sets is trivial

In the late nineties, Smale proposed a list of problems for the next century and, among these, it was conjectured that for every $r\ge 1$ a $C^r$-generic diffeomorphism has trivial centralizer. Our contribution here is to prove the triviality of $C^r$-centralizers on hyperbolic basic sets. In particular, $C^r$-generic transitive Anosov diffeomorphisms have a trivial $C^1$-centralizer. These results follow from a more general criterium for expansive homeomorphisms with the gluing orbit property. We also construct a linear Anosov diffeomorphism on $\mathbb T^3$ with discrete, non-trivial central…

传递中心化子与纤维化部分双曲系统

Transitive centralizers and fibered partially hyperbolic systems

本文证明了光滑微分同胚中心化子的刚性结果，分类了具有传递中心化子的微分同胚，并在幂零流形上 Anosov 微分同胚等距扩张的扰动及 3 维部分双曲系统中给出了中心化子的 Lie 群结构与分类。

Arithmetic properties of centralizers of diffeomorphisms of the half-line

Let f be a smooth diffeomorphism of the half-line fixing only the origin and Z^r_f its centralizer in the group of C^r diffeomorphisms. According to well-known results of Szekeres and Kopell, Z^1_f is always a one-parameter group, naturally identified to \R, (with f identified to 1). On the other hand, Z^r_f, for r greater or equal to 2, can be smaller: in [Se], Sergeraert constructed an f whose C^infty centralizer reduces to the infinite cyclic group generated by f (i.e Z^\infty_f identifies to \Z). In [Ey1], we adapted Sergeraert's construction to obtain an f whose C^r centralizer, for all r…

Centralizers of derived-from-Anosov systems on $\mathbb{T}^3$: rigidity versus triviality

In this paper, we study the centralizer of a partially hyperbolic diffeomorphism on $\mathbb{T}^3$ which is homotopic to an Anosov automorphism, and we show that either its centralizer is virtually trivial or such diffeomorphism is smoothly conjugate to its linear part.

Centralizers of hyperbolic and kinematic-expansive flows

We show generic $C^\infty$ hyperbolic flows (Axiom A and no cycles, but not transitive Anosov) commute with no $C^\infty$-diffeomorphism other than a time-t map of the flow itself. Kinematic expansivity, a substantial weakening of expansivity, implies that $C^0$ flows have quasi-discrete $C^0$-centralizer, and additional conditions broader than transitivity then give discrete $C^0$-centralizer. We also prove centralizer-rigidity: a diffeomorphism commuting with a generic hyperbolic flow is determined by its values on any open set.

On the centralizer of diffeomorphisms of the half-line

Let f be a smooth diffeomorphism of the half-line fixing only the origin and Z^r its centralizer in the group of C^r diffeomorphisms. According to well-known results of Szekeres and Kopell, Z^1 is a one-parameter group. On the other hand, Sergeraert constructed an f whose centralizer Z^r, $2\le r\le \infty$, reduces to the group generated by f. We show that Z^r can actually be a proper dense and uncountable subgroup of Z^1 and that this phenomenon is not scarce.

Pathology and asymmetry: centralizer rigidity for partially hyperbolic diffeomorphisms

We discover a rigidity phenomenon within the volume-preserving partially hyperbolic diffeomorphisms with $1$-dimensional center. In particular, for smooth, ergodic perturbations of certain algebraic systems -- including the discretized geodesic flows over hyperbolic manifolds and certain toral automorphisms with simple spectrum and exactly one eigenvalue on the unit circle, the smooth centralizer is either virtually $\mathbb Z^\ell$ or contains a smooth flow. At the heart of this work are two very different rigidity phenomena. The first was discovered in [2,3] for a class of volume-preserving …

Trivial centralizers for codimension-one attractors

We show that if $Λ$ is a codimension-one hyperbolic attractor for a $C^r$ diffeomorphism $f$, where $2\leq r\leq \infty$, and $f$ is not Anosov, then there is a neighborhood $\mathcal{U}$ of $f$ in $\mathrm{Diff}^r(M)$ and an open and dense set $\mathcal{V}$ of $\mathcal{U}$ such that any $g\in\mathcal{V}$ has a trivial centralizer on the basin of attraction for $Λ$.

部分双曲流的可达性与中心化子

Accessibility and centralizers for partially hyperbolic flows

本文证明了部分双曲流中稳定可达性的$C^1$稠密性，并由此推导出四类流中拓扑传递性、遍历性及中心化子平凡性的$C^1$稠密性。

仿射自同构的不变复结构：一个上循环观点

Invariant complex structures for affine automorphisms: a cocycle viewpoint

本文证明紧复流形上的全纯微分同胚若双Lipschitz共轭于齐性空间上的遍历仿射自同构，则共轭光滑；若该自同构弱混合，则诱导复结构左不变。应用包括全纯Anosov微分同胚的正则性提升及高秩交换Anosov作用的刚性定理的全纯类比。

具有二维中心的遍历环面自同构的扰动的拓扑中心化子

Topological centralizers of perturbations of ergodic toral automorphisms with two dimensional center

该研究针对具有二维中心的遍历环面自同构的C²²邻域内的微分同胚，证明了二分性结果，明确了其可达性与拓扑共轭的等价条件，给出了其中心化子的结构。

A Criterion For Ergodicity of Non-uniformly hyperbolic Diffeomorphisms

In this work we exhibit a new criteria for ergodicity of diffeomorphisms involving conditions on Lyapunov exponents and general position of some invariant manifolds. On one hand we derive uniqueness of SRB-measures for transitive surface diffeomorphisms. On the other hand, using recent results on the existence of blenders we give a positive answer, in the $C^1$ topology, to a conjecture of Pugh-Shub in the context of partially hyperbolic conservative diffeomorphisms with two dimensional center bundle.