I work in polyhedral geometry, at the crossroads of combinatorics, topology and algebra.
- Combinatorics: simplicial complexes, (delta-)matroids, graphs
- Geometry: polytopes, polyhedral fans, PL spheres, tropical varieties
- Topology: polyhedral products, moment-angle complexes, (topological) toric manifolds
- Linear algebra: $0/\pm1$-matrices, totally unimodular and totally equimodular matrices
- Algebra: Stanley–Reisner rings, Chow rings, algebraic groups, operads
Tropical geometry
Mukai Grassmannians and Mukai’s model for curves, tropically. Tropicalization turns an algebraic variety into a polyhedral complex that retains much of its geometry. We study the tropicalization of Mukai Grassmannians.
Ongoing: with Michael Joswig, Kevin Kuehn, Bernd Sturmfels.
Toric topology
Toric manifolds of small Picard number. Toric manifolds correspond to complete nonsingular fans, and their Picard number is the number of rays minus the dimension. We use the wedge operation on simplicial complexes to classify PL spheres and toric manifolds of small Picard number.
[slides] — with Suyoung Choi, Hyeontae Jang
Ongoing: enumeration of PL spheres and toric manifolds of small Picard number, with Suyoung Choi.
Combinatorial optimization
Box-integrality and integer decomposition. A polyhedron is box-integral if it stays integral after intersecting it with any integer box. I study the integer decomposition properties of such polyhedra via triangulations, box-total dual integrality, and totally equimodular (TE) matrices, a generalization of totally unimodular matrices.
[slides, poster] — with Patrick Chervet, Roland Grappe
Ongoing: recognition and characterization of TE matrices, with Roland Grappe.
Operad theory
Set-theoretic operads. Operads encode the operations acting on a category of algebras. I study operads on sets, in particular on simplicial complexes, and their action on polyhedral products, which give topological models for toric manifolds.
[slides]
Ph.D. thesis
- Title: Cones, fans, and wedges: combinatorial and geometrical perspectives
- Date defended: 9 September 2025
- Institution: LIPN (Laboratoire d’Informatique de Paris Nord), Université Sorbonne Paris Nord, France
- Advisors: Roland Grappe and Bruno Vallette
- Topics: combinatorial optimization, polyhedral geometry, toric geometry
- Manuscript: PDF