# The locus of post-critically finite maps in the moduli space of self-maps of $\mathbb{P}^n$

*Rohini Ramadas (Brown)*

**15-May-2020, 17:45-18:45 (4 years ago)**

**Abstract: **A degree $d>1$ self-map $f$ of $\mathbb{P}^n$ is called post critically finite (PCF) if its critical hypersurface $C_f$ is pre-periodic for $f$, that is, if there exist integers $r \geq 0$ and $k>0$ such that $f^{r+k}(C_f)$ is contained in $f^{r}(C_f)$.

I will discuss the question: what does the locus of PCF maps look like as a subset of the moduli space of degree $d$ maps on $\mathbb{P}^n$? I’ll give a survey of many known results and some conjectures in dimension $1$. I’ll then present a result, joint with Patrick Ingram and Joseph Silverman, that suggests that in dimensions two or greater, PCF maps are comparatively scarce in the moduli space of all self-maps.

algebraic geometrydynamical systems

Audience: researchers in the topic

( paper )

**Comments: **The discussion for Rohini Ramadas’s talk is taking place not in zoom-chat, but at tinyurl.com/2020-05-15-rr (and will be deleted after 3-7 days).

**Stanford algebraic geometry seminar **

**Series comments: **The seminar was online for a significant period of time, but for now is solely in person.
More seminar information (including slides and videos, when available): agstanford.com

Organizer: | Ravi Vakil* |

*contact for this listing |