English

A uniform Tits alternative for endomorphisms of the projective line

Number Theory 2025-04-22 v1 Dynamical Systems Group Theory

Abstract

A recent article of J.P. Bell, K. Huang, W. Peng and T.J. Tucker establishes an analog of the Tits alternative for semigroups of endomorphisms of the projective line. The proof involves a ping-pong argument on arithmetic height functions. Extending this method, we obtain a uniform version of the same alternative. In particular, we show that semigroups of End(P1)\mathrm{End}(\mathbb{P}^{1}) of exponential growth are of uniform exponential growth.

Keywords

Cite

@article{arxiv.2504.14263,
  title  = {A uniform Tits alternative for endomorphisms of the projective line},
  author = {Alonso Beaumont},
  journal= {arXiv preprint arXiv:2504.14263},
  year   = {2025}
}