75 citations · 305 across the 41 of their papers we have counts for
58 papers
The Hibi-Li Face-Number Conjecture
Ghislain Fourier
We prove the face-number conjecture of Hibi and Li: for every finite poset, the order polytope has no more faces of any given dimension than the chain polytope. More generally, the…
Makhlin polytopes are Demazure string polytopes
Ghislain Fourier
We show that Makhlin's polytopes in type are unimodularly equivalent to string polytopes for Demazure modules in type . The proof passes through type , combining…
On facet gaps of order and chain polytopes
Ghislain Fourier
We discuss three questions from a recent paper of Bhandari, Cunningham, Morrell, Oh and Smith. We obtain an exact local formula for the facet gap between the order and the chain po…
The Real Vanishing Ideals of Nuclear p-Norm Balls
Ghislain Fourier, Yuhuai Zhou
We study the algebraic and geometric structure related to tensor nuclear norms. We show that the unit ball of the nuclear norm is the convex hull of an irreducible real variety and…
Linear degenerate symplectic flag varieties: symmetric degenerations and PBW locus
Magdalena Boos, Giovanni Cerulli Irelli, Xin Fang +1
We conceptualize in the paper the linear degenerate symplectic flag varieties as symmetric degenerations within the framework of type equioriented quivers. First, in the larger…
Dynkin abelianisations of flag varieties
Shreepranav Varma Enugandla, Xin Fang, Ghislain Fourier +1
Cerulli Irelli and Lanini have shown that PBW degenerations of flag varieties in type A and C are actually Schubert varieties of higher rank. We introduce Dynkin cones to parameter…