17 research outputs found
On hyperbolic fixed points in ultrametric dynamics
Let K be a complete ultrametric field. We give lower and upper bounds for the
size of linearization discs for power series over K near hyperbolic fixed
points. These estimates are maximal in the sense that there exist examples
where these estimates give the exact size of the corresponding linearization
disc. In particular, at repelling fixed points, the linearization disc is equal
to the maximal disc on which the power series is injective.Comment: http://www.springerlink.com/content/?k=doi%3a%2810.1134%2fS2070046610030052%2
Linearization in ultrametric dynamics in fields of characteristic zero - equal characteristic case
Let be a complete ultrametric field of charactersitic zero whose
corresponding residue field is also of charactersitic zero. We give
lower and upper bounds for the size of linearization disks for power series
over near an indifferent fixed point. These estimates are maximal in the
sense that there exist exemples where these estimates give the exact size of
the corresponding linearization disc. Similar estimates in the remaning cases,
i.e. the cases in which is either a -adic field or a field of prime
characteristic, were obtained in various papers on the -adic case
(Ben-Menahem:1988,Thiran/EtAL:1989,Pettigrew/Roberts/Vivaldi:2001,Khrennikov:2001)
later generalized in (Lindahl:2009 arXiv:0910.3312), and in (Lindahl:2004
http://iopscience.iop.org/0951-7715/17/3/001/,Lindahl:2010Contemp. Math)
concerning the prime characteristic case
On the linearization of non-Archimedean holomorphic functions near an indifferent fixed point
We consider the problem of local linearization of power series defined over complete valued fields. The complex field case has been studied since the end of the nineteenth century, and renders a delicate number theoretical problem of small divisors related to diophantine approximation. Since a work of Herman and Yoccoz in 1981, there has been an increasing interest in generalizations to other valued fields like p-adic fields and various function fields. We present some new results in this domain of research. In particular, for fields of prime characteristic, the problem leads to a combinatorial problem of seemingly great complexity, albeit of another nature than in the complex field case. In cases for which linearization is possible, we estimate the size of linearization discs and prove existence of periodic points on the boundary. We also prove that transitivity and ergodicity is preserved under the linearization. In particular, transitivity and ergodicity on a sphere inside a non-Archimedean linearization disc is possible only for fields of p-adic numbers