Misiurewicz polynomials for rational maps with nontrivial automorphisms

Misiurewicz polynomials for rational maps with nontrivial automorphisms II

This paper continues discussions in the author's previous paper about the Misiurewicz polynomials defined for a family of degree $d \ge 2$ rational maps with an automorphism group containing the cyclic group of order $d$. In particular, we extend the sufficient conditions that the Misiurewicz polynomials are irreducible over $\mathbb{Q}$. We also prove that the Misiurewicz polynomials always have an irreducible factor of large degree.

Automorphism Groups of Endomorphisms of $\mathbb{P}^1 (\bar{\mathbb{F}}_p)$

For any algebraically closed field $K$ and any endomorphism $f$ of $\mathbb{P}^1(K)$ of degree at least 2, the automorphisms of $f$ are the Möbius transformations that commute with $f$, and these form a finite subgroup of $\operatorname{PGL}_2(K)$. In the moduli space of complex dynamical systems, the locus of maps with nontrivial automorphisms has been studied in detail and there are techniques for constructing maps with prescribed automorphism groups that date back to Klein. We study the corresponding questions when $K$ is the algebraic closure $\bar{\mathbb{F}}_p$ of a finite field. We use …

具有自同构的有理映射的一致有界性

Uniform boundedness on rational maps with automorphisms

针对自同构群含 d 阶循环群、次数 d≥2 的有理映射族，论文证明其某一子族满足动力学一致有界性原理。

Quartic K3 surfaces without nontrivial automorphisms

For any field k of characteristic at most 5 we exhibit an explicit smooth quartic surface in projective threespace over k with trivial automorphism group over the algebraic closure of k. We also show how this can be extended to higher characteristics. Over the rationals we construct an example on which the set of rational points is Zariski dense.

Computing conjugating sets and automorphism groups of rational functions

Let phi and psi be endomorphisms of the projective line of degree at least 2, defined over a noetherian commutative ring R with unity. From a dynamical perspective, a significant question is to determine whether phi and psi are conjugate (or to answer the related question of whether a given map phi has a nontrivial automorphism). We show that the space of automorphisms of P^1 conjugating phi to psi is a finite subscheme of PGL(2) (respectively that the automorphism group of phi is a finite group scheme). We construct efficient algorithms for computing the set of conjugating maps (resp. the gro…

具有简单雅可比矩阵的曲线的自同构群

Automorphism groups of curves with simple Jacobians

研究特征为0的代数闭域上具有简单雅可比矩阵的光滑射影连通曲线的自同构群，通过构造曲线族并证明其密度为1的成员集有简单雅可比矩阵，在主极化阿贝尔簇模空间中给出无限多个新的不太可能的交的例子。