Current position

Since 09/2018 :: Visiting assistant professor (ATER) at I2M (Institut de Mathématiques de Marseille).


Since 09/2018 :: Ph.D. in mathematics (ongoing), Aix-Marseille University. Classical realizability: new tools and applications. Advisor: Laurent Regnier. Defense: March 2019.

2011 – 2015 :: École Normale Supérieure diploma, École Normale Supérieure, Paris. Major: mathematics, minor: computer science.

2014 :: Research internship, Universidad de la República, Montevideo (Uruguay). Classical realizability in set theory: an example with the model of threads. Advisor: Alexandre Miquel.

2013 – 2014 :: Research Master (M2): Mathematical Logic and Foundations of Computer Science (LMFI), Paris Diderot University, École Normale Supérieure, Paris. With honours (Mention très bien).

2011 – 2013 :: University degree (L3 and M1) in mathematics, École Normale Supérieure, Paris.

2009 – 2011 :: CPGE (2-year program preparing for entry exams to engineering schools), Lycée Louis le Grand, Paris. Admitted to École Normale Supérieure, group MPI, rank 23rd.

2009 :: High-school diploma (baccalauréat général), scientific option, Lycée Évariste de Parny, Saint Paul (La Réunion, France). With honours (mention très bien, avec les félicitations du jury).


Peer-reviewed publications

07/2018 :: Guillaume Geoffroy. Classical realizability as a classifier for nondeterminism. LICS 2018: Thirty-First Annual ACM / IEEE Symposium on Logic in Computer Science.

Publications in preparation

Guillaume Geoffroy. Classical realizability: new tools and applications. Ph.D. thesis.

Laura Fontanella, Guillaume Geoffroy, Jean-Louis Krivine. Realizability models of ZF with weak forms of choice.


09/2018 :: Connecting degrees of parallelism and Boolean algebras through classical realizability, CHoCoLa.

07/2018 :: Classical realizability as a classifier for nondeterminism, LICS 2018.

06/2018 :: Clasical realizability and nondeterminism, Realizability in Marseille.

2016 :: Weekly workshop on classical realizability in the LDP (Logique de la programmation) team, I2M. Main speaker.

Scientific meetings

06/2018 :: Realizability in Marseille, co-organizer (with Laura Fontanella).

Science popularization

Co-founder and vice-president of Pi Day association (

2015 – 2017 :: President of Pi Day association.

14 March 2017 :: Co-author (with Joël Cohen) of the mathematical musical From Marseille to Vegas and co-organizer of the Pi Tour: three performances of the musical in Paris (théâtre des Variétés), Lyon (le Transbordeur) and Marseille (le Silo), accompanied by short scientific talks (attendance: 2000).

14 March 2016 :: Co-author of the mathematical musical Les π travaux d’Archimède and co-organizer of Pi Day in Marseille: one performance of the musical, accompanied by short scientific talks (attendance: 700). The association received the 2016 d’Alembert Award of the French Mathematical Society for this action.


Since 09/2018 :: Visiting assistant professor (ATER) at Aix-Marseille University (192h per year). Linear algebra; methodology; mathematical reasoning (1st year university – L1); C and systems programming (1st year university – L1); research initiation workshops (high school).

2015 – 2018 :: Teaching assistant (chargé de mission d’enseignement) at Aix-Marseille University (64h per year). Introductory analysis; algebra and geometry (1st year university – L1); C programming (1st and 2nd year university – L1 & L2); logic and computability (graduate course – M2); research initiation workshops (high school).


French (native), English, Spanish, Italian.

2017 – 2018 :: Oranizer of Café des langues de Luminy, daily multilingual student language exchange group.