5 papers
Schubitopes are not Ehrhart positive
Yupeng Li, Avery St. Dizier
Schubitopes are a family of generalized permutahedra arising as the Newton polytopes of both Schubert polynomials and Demazure characters of . Monical, Tokcan, and Y…
Counterexamples to Robichaux's conjecture for Grothendieck polynomials
Avery St. Dizier
Ross and Yong conjectured a -theoretic Kohnert rule for Grothendieck polynomials. Robichaux exhibited a counterexample to the Ross--Yong rule and proposed a revised ghost -Ko…
K-promotion on m-packed labelings of posets
Jamie Kimble, Bruce E. Sagan, Avery St. Dizier
Schutzenberger's promotion operator, pro, is a fundamental map in dynamical algebraic combinatorics. At first, its action was mainly considered on standard Young tableaux. But pro…
Log-concavity of characters of parabolic Verma modules, and of restricted Kostant partition functions
Apoorva Khare, Jacob P. Matherne, Avery St. Dizier
In 2022, Huh-Matherne-Mészáros-St. Dizier showed that normalized Schur polynomials are Lorentzian, thereby yielding their continuous (resp. discrete) log-concavity on the positiv…
Double orthodontia formulas and Lascoux positivity
Linus Setiabrata, Avery St. Dizier
We give a new formula for double Grothendieck polynomials based on Magyar's orthodontia algorithm for diagrams. Our formula implies a similar formula for double Schubert polynomial…