Guillaume Pignon--Ywanne

E-mail: guillaume (dot) pignon--ywanne (at) ens-lyon (dot) fr
Office: M1 406
CV : In English or in French (Last updated : July 2025)

I am Guillaume Pignon-Ywanne, currently a third-year PhD student at UMPA, under the co-supervision of Gabriel Dospinescu and Arthur-César Le Bras. Before that, I was a student at ENS Ulm and Sorbonne université.

My main area of work is in p-adic geometry, and I am interested in p-adic Hodge theory, representation theory, algebraic and arithmetic geometry, and Langlands correspondence.

(Pre)Publications

"Mod $p$ Poincaré duality for p-adic period domains" : Preliminary version available here. Still work in progress, expected to be on the arxiv by the end of 2025

Here are a few documents I wrote that might be of interest :

• My Master's thesis, "Extension groups of some period sheaves", under the supervision of W.Niziol, and based on this article by A-C. Le Bras and J. Anschütz (in English)


• A reader-friendly introduction to étale cohomology, relying on as little algebraic geometry background as I could (in French)


• My M1 thesis on Gudkov congruence in Hilbert's 16th problem (in French)


• A presentation on Lawvere fixed point theorem and some applications (in French)

Past teaching

• In spring 2025, I was a teaching assistant for a M1 course on Riemann Surfaces, by François Brunault

  All the information, as well and a deposit of the exercise sheets, are on the Portail des études.

• In fall of 2024, I was a teaching assistant (together with Iván Rosas Soto) for an undergraduate course on Complex Analysis by François Brunault. All the information, as well and a deposit of the exercise sheets, are on the corresponding page of the Portail des études

• In spring of 2024, I was a teaching assistant for an undergraduate (L3) course on Locally Compact Groups by Adrien Le Boudec. For more information and a deposit of the exercise sheets, see here

• In fall of 2023, I was a teaching assistant for an undergraduate (L3) course on Continued Fraction by Alexei Tsyvintsev. For more information and a deposit of the exercise sheets, see here