Kéva Djambaé
Doctoral Researcher in mathematicsEmail : djambae at gaati.org
GAATI Laboratory
University of French Polynesia
BP 6570 — 98702 Faaa
French Polynesia
Research
Research Interest
PhD studies are conducted under the supervision of
Gaetan Bisson and
David Kohel, member of the GAATI laboratory at the University of French Polynesia and of the Arithmetic and Information Theory (ATI) team within the Institute of Mathematics of Marseille (I2M).
A brief curriculum vitae (May 2026) is available here.
Research focuses on arithmetic geometry, a field at the intersection of algebraic number theory and algebraic geometry. The Master's thesis explored the generalization of the Kronecker-Weber theorem in the context of totally imaginary quadratic extensions, leveraging elliptic curves with complex multiplication. The thesis and a summary (in English) are available below:
My research focuses on abelian varieties, with a particular interest in the explicit construction of field automorphisms from isogeny cycles. This work offers new insights into the arithmetic structure of finite and local fields by linking isogeny theory to field extensions and Galois actions.
I am interested in both the computational and theoretical aspects, primarily using SageMath and Magma to generate concrete examples. My approach relies on a combination of class field theory and scheme theory, which allows me to explore the interactions between arithmetic invariants, field extensions, and geometric objects within a framework that is both concrete and unified.
Publications
Current Projects
- Automorphisms of local fields from isogeny cycles (2026?)
Preprints
- Automorphisms of finite fields from isogeny cycles (2026) (Submitted) <hal-05555215> <arXiv:2603.19428 >
- A note written for the 2026 UPF Doctoriales: “Automorphisms of finite fields from isogeny cycles” <hal-05581754>
Popularization
- Poster for the 2025 UPF Doctoriales titled “Elliptic Curves over Finite Fields”.<hal-05575112>
Talks
Upcoming presentations
- A 30 minutes presentation of my research at the Conseil économique, social et culturel de Polynésie française on May 21, 2026.
Past presentations
I have given several talks in various academic and outreach settings:
- A presentation at the 2026 UPF Doctoral Conference titled “Number Theory from a Geometric Perspective.” This event led to the publication of an article available here (in french) .
- Participation in the number theory seminar, on April 15th 2026, at the University of New South Wales in Sydney, Australia, entitled ”Explicit construction of Galois Group".
- An outreach talk during the SOUPAMES seminar organized by the ANU-CNRS France Australia Mathematical Sciences and Interactions International Research Lab in Canberra from April 7 to 10, 2026, titled “Number theory through the lens of geometry.”
- A 15-minute presentation at the SOUPAMES seminar organized by the ANU-CNRS France Australia Mathematical Sciences and Interactions International Research Lab in Canberra from April 7 to 10, 2026, entitled ”Explicit construction of Galois Group."
- A team seminar at the GAATI laboratory on January 26, 2026, entitled “Automorphisms of finite fields from elliptic curves.”
- A team seminar at the GAATI laboratory on May 13, 2025, entitled "Galois Action and Elliptic Curves" (notes to be published shortly), where I presented both my annual research progress and my Master's thesis work.
- A presentation at the 2025 UPF Doctoral Conference, aimed at a general audience. A recording is available here (my presentation starts at 27:30) with this poster.
- I organized a mathematical outreach workshop at the École de la Deuxième Chance in Marseille, at the invitation of J. Youssef, on July 22, 2022.
Teaching
2025/2026
In 2025/2026, I taught at the University of French Polynesia (UPF) in three tutorial sessions (TD) for the first year of the Mathematics – Engineering Sciences program.
Unless otherwise specified, the tutorial sheets were written by the professors in charge of the lectures:
First semester
- Numerical and Algebraic Calculus
Second semester
- Matrix Calculus
- Lecture given by Prescillia Tcheou
- TD
- A summary sheet on the determinants
- TD n°2 (Deepening and made by myself)
- Review sheet (Deepening and made by myself)
2024/2025
For the 2024/2025 academic year, tutorials are taught at the University of French Polynesia (UPF) as part of the first-year Bachelor's degree program for the Mathematics - Science for Engineering portal.
The tutorial sheets were written by those responsible for the lectures:
- Integral Calculus
- Lecture course taught by Jean Vallès
- TD 1
- TD 2
- TD 3
- Review sheet
- TD 4
- Review sheet 2 (made by Christophe Raffali and myself)
- Matrix Calculations
- Lecture course taught by Prescillia Tcheou
- TD
2023/2024
Teaching experience began at Lycée Honoré Daumier in Marseille, with responsibilities including a classe de seconde générale and two classes de première spécifique during the CAPES internship. Lecture notes (in French and partially complete due to time constraints) are provided below:
Institutional Commitments
Research Commission
Elected member representing PhD students of the Sciences, Technologies and Health (STS) sector to the Research Commission of the University of French Polynesia (2025–2027 term), contributing to discussions on scientific orientations, research evaluation and support, as well as doctoral student representation.
Disciplinary Commission
Elected member (students’ section) of the Disciplinary Commission of the University of French Polynesia (2025–2027 term), contributing to deliberations concerning compliance with academic obligations, the review of disciplinary matters, and the safeguarding of students’ rights.