5 papers
Polytopal bases for barycentric subdivisions
Spencer Backman, Federico Castillo
Several important fans studied at the interface of combinatorics and algebraic geometry arise from barycentric subdivisions of other fans; the central example is the braid arrangem…
A differential characterization of volume polynomials of permutohedra
Tristram Bogart, Federico Castillo, Damián de la Fuente +1
We study a graded vector space of polynomials associated to a square matrix, defined by a finite difference condition along the rows. We show this space coincides with one defined…
Paper BOAT
Federico Castillo, Damian de la Fuente, Nicolas Libedinsky +1
We derive a formula for computing the size of lower Bruhat intervals for elements in the dominant cone of an affine Weyl group of type . This enumeration problem is reduced to c…
Solving one-body ensemble N-representability problems with spin
Julia Liebert, Federico Castillo, Jean-Philippe Labbé +2
The Pauli exclusion principle is fundamental to understanding electronic quantum systems. It namely constrains the expected occupancies of orbitals according to $0 \le…
Symmetrizing polytopes and posets
Federico Castillo, Fu Liu
Motivated by the authors' work on permuto-associahedra, which can be considered as a symmetrization of the associahedron using the symmetric group, we introduce and study the $\mat…