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Related papers: Ehrhart positivity and Demazure characters

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A polynomial has saturated Newton polytope (SNP) if every lattice point of the convex hull of its exponent vectors corresponds to a monomial. We compile instances of SNP in algebraic combinatorics (some with proofs, others conjecturally):…

Combinatorics · Mathematics 2019-12-03 Cara Monical , Neriman Tokcan , Alexander Yong

We present a Hilbert space geometric approach to the problem of characterizing the positive bivariate trigonometric polynomials that can be represented as the square of a two variable polynomial possessing a certain stability requirement,…

Complex Variables · Mathematics 2016-03-21 Jeffrey S. Geronimo , Plamen Iliev , Greg Knese

Several polytopes arise from finite graphs. For edge and symmetric edge polytopes, in particular, exhaustive computation of the Ehrhart polynomials not merely supports the conjecture of Beck {\it et al.}\ that all roots $\alpha$ of Ehrhart…

Combinatorics · Mathematics 2015-03-13 Tetsushi Matsui , Akihiro Higashitani , Yuuki Nagazawa , Hidefumi Ohsugi , Takayuki Hibi

We study a family of polynomials whose values express degrees of Schubert varieties in the generalized complex flag manifold G/B. The polynomials are given by weighted sums over saturated chains in the Bruhat order. We derive several…

Combinatorics · Mathematics 2007-05-23 Alexander Postnikov , Richard P. Stanley

We study a class of bivariate deformed Hermite polynomials and some of their properties using classical analytic techniques and the Wigner map. We also prove the positivity of certain determinants formed by the deformed polynomials. Along…

Mathematical Physics · Physics 2014-10-21 S. Twareque Ali , Mourad E. H. Ismail , Nurisya M. Shah

To any Schur polynomial $s_{\lambda}$ one can associated its derived polynomials $s_{\lambda}{(i)}$ $i=0,\ldots,|\lambda|$ by the rule $$s_{\lambda}(x_1+t,\ldots,x_n+t) = \sum_i s_{\lambda}^{(i)}(x_1,\ldots,x_n) t^i.$$ We conjecture that…

Combinatorics · Mathematics 2024-03-08 Julius Ross , Kuang-Yu Wu

Ehrhart polynomials are extensively-studied structures that interpolate the discrete volume of the dilations of integral $n$-polytopes. The coefficients of Ehrhart polynomials, however, are still not fully understood, and it is not known…

Combinatorics · Mathematics 2021-01-22 Fiona Abney-McPeek , Sanket Biswas , Senjuti Dutta , Yongyuan Huang , Deyuan Li , Nancy Xu

We show that when integral polytopes are deformed while keeping the same facet normal vectors, the coefficients of weighted Ehrhart and $h^*$-polynomials are piecewise polynomial functions in the ``right hand sides'' of the linear…

Combinatorics · Mathematics 2025-11-14 Daniel Hwang , Juliet Whidden , Josephine Yu

We investigate properties of Ehrhart polynomials for matroid polytopes, independence matroid polytopes, and polymatroids. In the first half of the paper we prove that for fixed rank their Ehrhart polynomials are computable in polynomial…

Combinatorics · Mathematics 2017-01-03 Jesús A. De Loera , David C. Haws , Matthias Köppe

We conduct a systematic study of the Ehrhart theory of certain slices of rectangular prisms. Our polytopes are generalizations of the hypersimplex and are contained in the larger class of polypositroids introduced by Lam and Postnikov;…

Combinatorics · Mathematics 2025-04-30 Luis Ferroni , Daniel McGinnis

The Ehrhart polynomial of an integral convex polytope counts the number of lattice points in dilates of the polytope. In math.CO/0402148, the authors conjectured that for any cyclic polytope with integral parameters, the Ehrhart polynomial…

Combinatorics · Mathematics 2007-05-23 Fu Liu

We suggest to associate with each knot the set of coefficients of its HOMFLY polynomial expansion into the Schur functions. For each braid representation of the knot these coefficients are defined unambiguously as certain combinations of…

High Energy Physics - Theory · Physics 2013-03-21 A. Mironov , A. Morozov , An. Morozov

In Ehrhart theory, the well-known sign pattern problem asks: given a positive integer $d\geq 3$ and integers $1 \leq i_1 < \cdots < i_k \leq d-2$, does there exist a $d$-dimensional integral polytope $\mathcal{P}$ such that in its Ehrhart…

Combinatorics · Mathematics 2026-05-26 Feihu Liu , Sihao Tao , Guoce Xin

Stanley's non-negativity theorem is at the heart of many of the results in Ehrhart theory. In this paper, we analyze the root behavior of general polynomials satisfying the conditions of Stanley's theorem and compare this to the known root…

Combinatorics · Mathematics 2010-07-23 Benjamin Braun , Mike Develin

One definition of key polynomials is as the weight generating functions of key tableaux. Assaf and Schilling introduced a crystal structure on key tableaux and related it to Morse--Schilling crystals on reduced factorizations for…

Combinatorics · Mathematics 2024-06-18 Jiayi Wen

One approach to Schubert calculus is to realize Schubert classes as concrete combinatorial objects such as Schubert polynomials. Through an identification of the cohomology ring of the type A full flag variety with the polytope ring of the…

Representation Theory · Mathematics 2020-08-12 Naoki Fujita

The Pieri rule is a nonnegative, multiplicity-free formula for the Schur function expansion of the product of an arbitrary Schur function with a single row Schur function. Key polynomials are characters of Demazure modules for the general…

Combinatorics · Mathematics 2019-08-23 Sami Assaf , Danjoseph Quijada

Some Dirichlet-like functions, attached to a pair (periodic function, polynomial) are introduced and studied. These functions generalize the standard Dirichlet L-functions of Dirichlet characters. They have similar properties, being…

Number Theory · Mathematics 2025-03-25 Frédéric Chapoton

Generalizing a conjecture by De Loera et al., we conjecture that integral generalized permutohedra all have positive Ehrhart coefficients. Berline and Vergne construct a valuation that assigns values to faces of polytopes, which provides a…

Combinatorics · Mathematics 2017-10-17 Federico Castillo , Fu Liu

It is shown that, for each $d \geq 4$, there exists an integral convex polytope $\mathcal{P}$ of dimension $d$ such that each of the coefficients of $n, n^{2}, \ldots, n^{d-2}$ of its Ehrhart polynomial $i(\mathcal{P},n)$ is negative.

Combinatorics · Mathematics 2014-01-03 Takayuki Hibi , Akihiro Higashitani , Akiyoshi Tsuchiya , Koutarou Yoshida