General information

The workshop is a part of the Simons semester program Varieties: $\mathbb{A}$rithmetic and $\mathbb{T}$ransformations held at IMPAN, Warsaw. The aim is to bring together people interested in learning the theory of $F$-isocrystals in order to get a quick and intense start. The approach is to look at the recent results concerning Newton polygons of $F$-isocrystals on abelian varieties from two different perspectives: geometric given by Tsuzuki and Tannakian provided in the paper by d'Addezio. We also plan to have three research level lectures by Marco d'Addezio, Christopher Lazda and Atsushi Shiho. For the precise program, please take a look below.

We encourage all interested people to volunteer to give one of the talks. We hope to establish the whole speaking squad by Sunday 21st Oct. If you want to book a spot, discuss the content of the lectures or ask any other question concerning the workshop's program please write to the organizers.


The workshop will take place in Institute of Mathematics, Polish Academy of Sciences, ul. Śniadeckich 8, Warsaw. The precise room number will be announced before the event.

Financial support:

Unfortunately, we cannot provide any financial support for the participants.


The meeting is partially funded by Banach Center.
The event is organized by Piotr Achinger (IMPAN Warsaw) and Maciej Zdanowicz (EPF Lausanne)
All inquiries should be directed to maciej.zdanowicz [at] epfl [dot] ch

Program of the workshop

Here's the program of the workshop. Note the schedule difference on Tuesday. We invite everyone to take part in Nathan Ilten's lecture at 10:30 that day.

Monday Tuesday Wednesday
Introductory talk
after Kedlaya's notes
Speaker: Maciej Zdanowicz
Tannakian formalism and isocrystal fundamental group
after Deligne, Milne "Tannakian Categories"
Speaker: Christopher Lazda
Purity for Newton polygons
after de Jong, Oort "Purity of the stratification by Newton polygons"
Speaker: Piotr Achinger
$F$-isocrystals over a field, Dieudonné-Manin classification
after Kedlaya's $p$-adic Differential Equations
Speaker: Jędrzej Garnek
$F$-isocrystals and $p$-adic representations of the fundamental group
after Crew's "$F$-isocrystals and $p$-adic representations"
Speaker: Maciej Zdanowicz
Families of curves over abelian varieties after Tsuzuki "Constancy of Newton polygons of $F$-isocrystals on abelian varieties ..."
Speaker: Adrian Langer
Overconvergence and examples
after Crew's "$F$-isocrystals on the affine line" and Chiarellotto-Christol
Speaker: Atsushi Shiho
Research talk: Atsushi Shiho
Research talk: Marco d'Addezio
Research talk: Christopher Lazda
Global monodromy theorem for overconvergent $F$-isocrystals
after Crew's "$F$-isocrystals and their monodromy"
Speaker: Marco d'Addezio


The following papers and notes could be useful during the preparation for the workshop.