English

Connected components of Berkovich fixed locus: Potential good reduction

Dynamical Systems 2026-01-13 v2 Algebraic Geometry Number Theory

Abstract

Let \mathbbmP1,an\mathbbm{P}^{1,an} be the Berkovich projective line over a complete, algebraically closed, non-Archimedean field. Let ϕ\phi be a degree 2\geq 2 rational map with potential good reduction, acting on \mathbbmP1,an\mathbbm{P}^{1,an}. In this article, we study the topology of the fixed locus of ϕ\phi. we show that the reduction of ϕ\phi at its type~II totally ramified fixed point dictates the topological structure of the fixed locus of ϕ\phi. We give an easily verifiable equivalent criterion for the fixed locus of ϕ\phi to be connected as well as an equivalent criterion for the fixed locus of ϕ\phi to be finite. Moreover, we provide a sharp upper bound for the number of connected components of the fixed locus of a rational map with potential good reduction.

Keywords

Cite

@article{arxiv.2508.07156,
  title  = {Connected components of Berkovich fixed locus: Potential good reduction},
  author = {Niladri Patra},
  journal= {arXiv preprint arXiv:2508.07156},
  year   = {2026}
}

Comments

20 Pages. The entire article has been reorganised from the last version. Comments are very much appreciated

R2 v1 2026-07-01T04:42:47.894Z