Lionel Lang
Senior lecturer
About the researcher
Before coming to Gävle, I was a postdoctoral fellow and then senior lecturer at Stockholm University, from 2017 to 2020. Before that, I was a postdoctoral fellow at Uppsala University, from 2015 to 2017. In December 2014, I finished my doctoral studies at the University of Geneva, Switzerland. My supervisor was Professor Grigory Mikhalkin.
Lionel Lang is currently working on his project entitled "Tropical compactifications of moduli spaces". This project is financed by the Swedish Research Council, from 2024 to 2027.
Tropical compactifications of moduli spaces
Algebraic geometry is a fundamental area of mathematics that aims at understanding the relations between shapes (geometry) and equations (algebra). Tropical geometry is a simplified version of algebraic geometry that emerged 20 years ago. There is a procedure called tropicalisation that transforms the shapes of algebraic geometry into the shapes of tropical geometry. The latter remember the core structure of their algebraic counterparts but forget about information that is often irrelevant in many problems.
Many long-standing problems in algebraic geometry have been solved using tropical geometry, making the latter a very active field of research. However, the relation between algebraic and tropical geometries still lacks theoretical foundations. Our goal is to unify these two geometries by constructing tropical compactifications of moduli spaces.
A moduli space is a set that encodes all possible shapes of the same nature. Our goal is to construct new spaces, the aforementioned compactifications, by gluing together algebraic and tropical moduli spaces, taking tropicalisation into account. These compactifications should:
- provide the correct translation of a problem in algebraic geometry to a problem in tropical geometry
- guarantee that a solution to the tropical problem provides a solution to the original problem.
Since problems in tropical geometry are often much easier to solve, tropical compactifications of moduli spaces have countless applications to algebraic geometry.
Sound interesting? Email Lionel Lang for more information.
I am a senior lecturer of mathematics at the University of Gävle. My research focuses on the connections between algebraic geometry and tropical geometry. I work on tropical compactifications of moduli space and their application to classical problems such as:
- Tropical compactification of moduli spaces.
- the computation of Galois groups and more generally monodromy groups of algebraic families
- the Severi problem on toric surfaces
I am also interested in the study of (mathematical) amoebas from the point of view of topology, singularity theory and symplectic geometry.
Talks and seminars
Towards tropical compactifications of moduli spaces (2024-05-03)
Occasion: MaP-Trop II seminar, A one-day symposium on Matroids, Polytopes and Tropical Geometry
Place: KTH, Stockholm, Sweden
More information about the seminar External link.
Towards tropical compactifications of moduli spaces (2024-04-24)
Occasion: MAM seminar
Place: Mälardalen University, Västerås, Sweden
Towards tropical compactifications of moduli spaces (2024-04-17)
Occasion: Algebraic geometry and number theory seminar
Place: Chalmers & Göteborgs universitet, Göteborg , Sweden
More information about the seminar External link.
2023-10-23
Title: Galois groups of systems of polynomial equations
Occasion: Coloquio de matemáticas UNIANDES
Place: Bogota, Columbia
https://math.uniandes.edu.co/app/coloquio/?id=2023-II
2023-09-20
Title: Galois groups of systems of polynomial equations
Occasion: Matematiska kollokviet, Linköpings universitet
Place: Linköping, Sweden
https://liu.se/artikel/matematiska-kollokviet
2023-07-04
Title: Measuring holes of hypersurfaces
Ocsasion: 29th Nordic Congress of mathematician (special session Symplectic & contact geometry & physics)
Place: Aalborg, Denmark
https://coms.events/NCM29/data/abstracts/en/abstract_0020.html
2023-06-16
Title: Braid monodromy of polynomial systems
Occasion: Topology and real algebraic geometry in low dimension (on the occasion of 75th anniversary of Oleg Viro)
Place: Institut Mittag-Leffler, Djursholm, Sweden
https://riemann.unizar.es/115AM/program.html
2023-06-16
Title: Braid monodromy of polynomials
Occasion: Algebraic and topological interplay of algebraic varieties
(A Conference in Honor of the 60th Birthday of Enrique Artal and the 55th Birthday of Alejandro Melle)
Place: Jaca, Spain
https://riemann.unizar.es/115AM/program.html
2023-04-26
Title: Measuring holes of hypersurfaces
Occasion: Geneva-Neuchâtel Symplectic Geometry seminar
Place: Geneva, Switzerland
https://www.unige.ch/math/tggroup/doku.php?id=symplectic
This page was last updated 2024-05-15