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Research presentation

Lionel Lang

Research presentation

Lionel Lang

Senior lecturer

Research subject: Mathematics

I am an associate professor 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:

  • 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.

Before coming to Gävle, I was a post-doc and then a non-tenured assistant professor at Stockholm University, from 2017 to 2020. Before that, I was a post-doc at Uppsala University, from 2015 to 2017. I received my PhD from the university of Geneva, Switzerland, in December 2014. My advisor was Professor Grigory Mikhalkin.



  • Publications


Scholarly articles, refereed

Lang, L. & Tyomkin, I. (2023). A note on the Severi problem for toric surfaces. Mathematische Annalen, 385, 1677-1705. 10.1007/s00208-022-02374-z [More information]
Lang, L. & Renaudineau, A. (2022). Patchworking the Log-critical locus of planar curves. Journal für die Reine und Angewandte Mathematik, 792, 115-143. 10.1515/crelle-2022-0054 [More information]
Esterov, A. & Lang, L. (2022). Sparse polynomial equations and other enumerative problems whose Galois groups are wreath products. Selecta Mathematica, New Series, 28 (2). 10.1007/s00029-021-00741-3 [More information]
Esterov, A. & Lang, L. (2021). Braid monodromy of univariate fewnomials. Geometry and Topology, 25 (6), 3053-3077. 10.2140/gt.2021.25.3053 [More information]
Lang, L., Shapiro, B. & Shustin, E. (2021). On the number of intersection points of the contour of an amoeba with a line. Indiana University Mathematics Journal, 70 (4), 1335-1353. 10.1512/iumj.2021.70.8627 [More information]
Lang, L. (2020). Harmonic tropical morphisms and approximation. Mathematische Annalen, 377 (1-2), 379-419. 10.1007/s00208-020-01971-0 [More information]
Lang, L. (2020). Monodromy of rational curves on toric surfaces. Journal of Topology, 13 (4), 1658-1681. 10.1112/topo.12171 [More information]
Lang, L. (2019). Amoebas of curves and the Lyashko-Looijenga map. Journal of the London Mathematical Society, 100 (1), 301-322. 10.1112/jlms.12214 [More information]
Crétois, R. & Lang, L. (2019). The vanishing cycles of curves in toric surfaces II. Journal of Topology and Analysis (JTA), 11 (04), 909-927. 10.1142/S1793525319500353 [More information]
Cretois, R. & Lang, L. (2018). The vanishing cycles of curves in toric surfaces I. Compositio Mathematica, 154 (8), 1659-1697. 10.1112/S0010437X18007200 [More information]
Published by: Camilla Haglund Page responsible: Gunilla Mårtensson Updated: 2022-07-04
Högskolan i Gävle
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