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Related papers: K-classes of matroids and equivariant localization

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We use the geometry of the stellahedral toric variety to study matroids. We identify the valuative group of matroids with the cohomology ring of the stellahedral toric variety, and show that valuative, homological, and numerical equivalence…

Algebraic Geometry · Mathematics 2023-09-08 Christopher Eur , June Huh , Matt Larson

In this article, we start to recall the inversion formula for the convolution with the Box spline. The equivariant cohomology and the equivariant K-theory with respect to a compact torus G of various spaces associated to a linear action of…

Differential Geometry · Mathematics 2015-03-17 C. De Concini , C. Procesi , M. Vergne

Symmetric $k$-varieties generalize Riemannian sym\-me\-tric spaces to reductive groups defined over arbitrary fields. For most perfect fields, it is known that symmetric $k$-varieties are in one-to-one correspondence with isomorphy classes…

Group Theory · Mathematics 2015-10-02 Nathaniel Schwartz

Thin sums matroids were introduced to extend the notion of representability to non-finitary matroids. We give a new criterion for testing when the thin sums construction gives a matroid. We show that thin sums matroids over thin families…

Combinatorics · Mathematics 2012-04-30 Hadi Afzali , Nathan Bowler

We introduce the self-projecting Grassmannian, an irreducible subvariety of the Grassmannian parametrizing linear subspaces that satisfy a generalized self-duality condition. We study its relation to classical moduli spaces, such as the…

Algebraic Geometry · Mathematics 2025-11-27 Alheydis Geiger , Francesca Zaffalon

We show that there is no triangulation of the infinite real Grassmannian of k-planes in R^\infty which is nicely situated with respect to the coordinate axes. In terms of matroid theory, this says there is no triangulation of the…

Geometric Topology · Mathematics 2015-11-30 Laura Anderson , James F. Davis

Networks are frequently studied algebraically through matrices. In this work, we show that networks may be studied in a more abstract level using results from the theory of matroids by establishing connections to networks by decomposition…

Combinatorics · Mathematics 2015-11-17 Konstantinos Papalamprou , Leonidas Pitsoulis

This article is a survey of matroid theory aimed at algebraic geometers. Matroids are combinatorial abstractions of linear subspaces and hyperplane arrangements. Not all matroids come from linear subspaces; those that do are said to be…

Algebraic Geometry · Mathematics 2014-09-12 Eric Katz

For a closed locally symmetric space M=\Gamma\G/K and a representation of G we consider the push-forward of the fundamental class in the homology of the linear group and a related invariant in algebraic K-theory. We discuss the…

Geometric Topology · Mathematics 2014-10-01 Thilo Kuessner

We give positive formulas for the restriction of a Schubert Class to a T-fixed point in the equivariant K-theory and equivariant cohomology of the Lagrangian Grassmannian. Our formulas rely on a result of Ghorpade-Raghavan, which gives an…

Algebraic Geometry · Mathematics 2007-05-23 V. Kreiman

The thagomizer matroid, realized as the graphic matroid of the complete tripartite graph $K_{1,1,n}$, has full automorphism group isomorphic to the hyperoctahedral group whenever $n \ge 2$. In the equivariant setting for this action, we…

Combinatorics · Mathematics 2026-02-12 Matthew H. Y. Xie , Philip B. Zhang , Michael X. X. Zhong

We introduce the Z-polynomial of a matroid, which we define in terms of the Kazhdan-Lusztig polynomial. We then exploit a symmetry of the Z-polynomial to derive a new recursion for Kazhdan-Lusztig coefficients. We solve this recursion,…

Combinatorics · Mathematics 2017-06-20 Nicholas Proudfoot , Ben Young , Yuan Xu

We introduce a notion of duality (due to Brylawski) that generalizes matroid duality to arbitrary rank functions. This generalized duality allows for generalized operations (deletion and contraction) and a generalized polynomial based on…

Combinatorics · Mathematics 2012-01-10 Gary Gordon

We consider a specialization $Y_M(q,t)$ of the Tutte polynomial of a matroid $M$ which is inspired by analogy with the Potts model from statistical mechanics. The only information lost in this specialization is the number of loops of $M$.…

Combinatorics · Mathematics 2016-09-07 David G. Wagner

In this paper, we introduce the concept of the Tutte polynomials of genus $g$ and discuss some of its properties. We note that the Tutte polynomials of genus one are well-known Tutte polynomials. The Tutte polynomials are matroid…

Combinatorics · Mathematics 2019-08-16 Tsuyoshi Miezaki , Manabu Oura , Tadashi Sakuma , Hidehiro Shinohara

We first retell in the K-theoretic context the heuristics of $S^1$-equivariant Floer theory on loop spaces which gives rise to $D_q$-module structures, and in the case of toric manifolds, vector bundles, or super-bundles to their explicit…

Algebraic Geometry · Mathematics 2015-09-15 Alexander Givental

Given a set of prime numbers S, we localise equivariant bivariant Kasparov theory at S and compare this localisation with Kasparov theory by an exact sequence. More precisely, we define the localisation at S to be KK^G(A,B) tensored with…

K-Theory and Homology · Mathematics 2012-06-29 Hvedri Inassaridze , Tamaz Kandelaki , Ralf Meyer

We extend the notion of representation of a matroid to algebraic structures that we call skew partial fields. Our definition of such representations extends Tutte's definition, using chain groups. We show how such representations behave…

Combinatorics · Mathematics 2012-12-12 R. A. Pendavingh , S. H. M. van Zwam

In this paper, we investigate the classes of matroid intersection admitting a solution for the problem of partitioning the ground set $E$ into $k$ common independent sets, where $E$ can be partitioned into $k$ independent sets in each of…

Combinatorics · Mathematics 2019-01-29 Kenjiro Takazawa , Yu Yokoi

Boij-S\"oderberg theory characterizes syzygies of graded modules and sheaves on projective space. This paper continues earlier work with S. Sam, extending the theory to the setting of $GL_k$-equivariant modules and sheaves on Grassmannians.…

Algebraic Geometry · Mathematics 2019-02-20 Nic Ford , Jake Levinson