Abstract

Subword complexes are simplicial complexes introduced by Knutson and Miller to illustrate the combinatorics of Schubert polynomials and determinantal ideals. They proved that any subword complex is homeomorphic to a ball or a sphere and asked about their geometric realizations. We show that a family of subword complexes can be realized geometrically via regular triangulations of root polytopes. This implies that a family of $\beta$-Grothendieck polynomials are special cases of reduced forms in the subdivision algebra of root polytopes. We can also write the volume and Ehrhart series of root polytopes in terms of $\beta$-Grothendieck polynomials.

Highlights

  • In this paper we provide geometric realizations of pipe dream complexes PD (π) of permutations π = 1π, where π is a dominant permutation on 2, 3, . . . , n as well as the subword complexes that are the cores of the pipe dream complexes PD (π)

  • Subword complexes are simplicial complexes introduced by Knutson and Miller in [10, 11] to illustrate the combinatorics of Schubert polynomials and determinantal ideals

  • Subword complexes were first shown to relate to triangulations of root polytopes by Mészáros in [17], where the author gives a geometric realization of the pipe dream complex of [1, n, n − 1, . . . , 2] and whose work served as the stepping stone for the present project

Read more

Summary

Introduction

In this paper we provide geometric realizations of pipe dream complexes PD (π) of permutations π = 1π , where π is a dominant permutation on 2, 3, . We realize PD (π) as (repeated cones of) regular triangulations of the root polytopes P(T (π)). Subword complexes were first shown to relate to triangulations of root polytopes by Mészáros in [17], where the author gives a geometric realization of the pipe dream complex of [1, n, n − 1, .

Background on pipe dream complexes
Background on root polytopes
Pipe dream complexes as triangulations of root polytopes
Reduced forms in the subdivision algebra and Grothendieck polynomials
Volumes and Ehrhart series of root polytopes
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call