6 papers
Symmetric edge polytopes are not gamma-positive
Luis Ferroni
A conjecture posed by Ohsugi and Tsuchiya (2019) postulates that the Ehrhart -polynomials of symmetric edge polytopes are -positive. We disprove this conjecture by exhibit…
Ehrhart positivity for lattice path matroids
Luis Ferroni, Alejandro H. Morales, Greta Panova
We prove that all lattice path matroids are Ehrhart positive. This unifies and generalizes numerous results on the Ehrhart positivity of matroids developed over the last two decade…
Luck and magic for Pitman-Stanley polytopes and parking functions
Nicolas Avila, Luis Ferroni, Alejandro H. Morales
Motivated by the combinatorics of parking functions and their several generalizations, we study the Ehrhart theory of Pitman--Stanley polytopes. We prove a strong positivity phenom…
Eulerian posets and -polynomials
Luis Ferroni, Roberto Riccardi
Let be a finite partially ordered set. In a recent series of works, Proudfoot introduced the notion of -polynomials associated with -kernels, providing a unified framewor…
Preservation of log-concavity on gamma polynomials
Luis Ferroni, Greta Panova, Lorenzo Venturello
Every symmetric polynomial with center of symmetry can be expressed as a linear combination in the basis . The -polynomial of , which we den…
Skew shapes, Ehrhart positivity and beyond
Luis Ferroni, Alejandro H. Morales, Greta Panova
A classical result by Kreweras (1965) allows one to compute the number of plane partitions of a given skew shape and bounded parts as certain determinants. We prove that these dete…