English

Examples of diffeomorphism group cocycles with no periodic approximation

Dynamical Systems 2017-05-23 v2

Abstract

We construct a finitely generated subgroup of Diff(S3×S1)\text{Diff}^{\infty}(\mathbb{S}^3 \times \mathbb{S}^1) where every element is conjugate to an isometry but such that the group action itself is far from isometric (the group has "exponential growth of derivatives"). As a corollary, one obtains a locally constant Diff(S3×S1)\text{Diff}^{\infty}(\mathbb{S}^3 \times \mathbb{S}^1) valued cocycle over a hyperbolic dynamical system which has elliptic behavior over its periodic orbits but which preserves a measure with non-zero top Fiber Lyapunov exponent. Additionally, we provide new examples of Banach cocycles not satisfying the periodic approximation property as first shown by Kalinin-Sadovskaya.

Keywords

Cite

@article{arxiv.1705.06361,
  title  = {Examples of diffeomorphism group cocycles with no periodic approximation},
  author = {Sebastian Hurtado},
  journal= {arXiv preprint arXiv:1705.06361},
  year   = {2017}
}
R2 v1 2026-06-22T19:50:31.479Z