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The Chow polynomial of a matroid is a fundamental invariant whose coefficients exhibit strong positivity properties, including $\gamma$-positivity. We interpret the normalized Chow coefficients as a probability distribution and establish…

Combinatorics · Mathematics 2026-04-30 Ronnie Cheng , Wangyang Lin

Lop\'ez de Medrano-Rin\'con-Shaw defined Chern-Schwartz-MacPherson cycles for an arbitrary matroid $M$ and proved by an inductive geometric argument that the unsigned degrees of these cycles agree with the coefficients of $T(M;x,0)$, where…

Combinatorics · Mathematics 2022-07-21 Ahmed Umer Ashraf , Spencer Backman

The Chern number is often used to distinguish between different topological phases of matter in two-dimensional electron systems. A fast and efficient coupling-matrix method is designed to calculate the Chern number in finite crystalline…

Disordered Systems and Neural Networks · Physics 2018-09-13 Y. F. Zhang , Y. Y. Yang , Yan Ju , L. Sheng , D. N. Sheng , R. Shen , D. Y. Xing

We define Chern-Schwartz-MacPherson (CSM) cycles of an arbitrary matroid. These are balanced weighted fans supported on the skeleta of the corresponding Bergman fan. In the case that the matroid arises from a complex hyperplane arrangement…

Combinatorics · Mathematics 2019-08-14 Lucia Lopez de Medrano , Felipe Rincon , Kristin Shaw

We provide a formula for the Poincar\'e dual of the Chern-Schwartz-MacPherson (CSM) cycle of a matroid in the Chow ring of the matroid. We derive the formula from the case of matroids realizable over the complex numbers and prove that it…

Combinatorics · Mathematics 2024-11-15 Franquiz Caraballo Alba , Jeffery Liu

Motivated by work in graph theory, we define the fixing number for a matroid. We give upper and lower bounds for fixing numbers for a general matroid in terms of the size and maximum orbit size (under the action of the matroid automorphism…

Combinatorics · Mathematics 2014-05-27 Gary Gordon , Jennifer McNulty , Nancy Ann Neudauer

We determine all Chern numbers of smooth complex projective varieties of dimension at least four which are determined up to finite ambiguity by the underlying smooth manifold. We also give an upper bound on the dimension of the space of…

Algebraic Geometry · Mathematics 2018-10-31 Stefan Schreieder , Luca Tasin

Combinatorial ideas are developed in this article to study Chern numbers on ample and numerically effective vector bundles. An effective lower bound for Chern numbers of ample vector bundles is established, which makes some progress towards…

Differential Geometry · Mathematics 2025-07-30 Ping Li

We show by example that the Chern numbers c_1^3 and c_1 c_2 of a complex 3-fold are not determined by the topology of the underlying smooth compact 6-manifold. In fact, we observe that infinitely many different values of a Chern number can…

Algebraic Geometry · Mathematics 2007-05-23 Claude LeBrun

We show that the number of linear spaces on a set of $n$ points and the number of rank-3 matroids on a ground set of size $n$ are both of the form $(cn+o(n))^{n^2/6}$, where $c=e^{\sqrt 3/2-3}(1+\sqrt 3)/2$. This is the final piece of the…

Combinatorics · Mathematics 2024-05-31 Matthew Kwan , Ashwin Sah , Mehtaab Sawhney

We introduce the rank-nullity ring of a matroid $M$, which is a subring of the Chow ring of the permutahedral toric variety. This subring contains the tautological Chern classes of $M$, a fact we deduce from a highly symmetric formula for…

Combinatorics · Mathematics 2026-01-19 Tara Fife , Eline Mannino , Felipe Rincón

Libgober and Wood proved that the Chern number $c_{1}c_{n-1}$ of a $n$-dimensional compact complex manifold can be determined by its Hirzebruch $\chi_{y}$-genus. Inspired by the idea of their proof, we show that, for compact, spin,…

Differential Geometry · Mathematics 2018-10-18 Ping Li

We show that every set of numbers that occurs as the set of Chern numbers of an almost complex manifold $M^{2n}$, $n\geqslant 3$, may be realized as the set of Chern numbers of a connected almost complex manifold with an almost complex…

Algebraic Topology · Mathematics 2015-06-18 Andrey Kustarev

The purpose of this short note is to prove a formula for the Chern-Mather classes of a toric variety in terms of its orbits and the local Euler obstructions at general points of each orbit (Theorem 2). We use the general definition of the…

Algebraic Geometry · Mathematics 2016-04-12 Ragni Piene

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

We discuss methods for calculating Chern numbers of two-dimensional lattice systems using spiral boundary conditions, which sweep all lattice sites in one-dimensional order. Specifically, we establish the one-dimensional representation of…

Strongly Correlated Electrons · Physics 2024-01-24 Masaaki Nakamura , Shohei Masuda

In order to study continuous models of disordered topological phases, we construct an unbounded Kasparov module and a semifinite spectral triple for the crossed product of a separable $C^*$-algebra by a twisted $\mathbb{R}^d$-action. The…

Mathematical Physics · Physics 2018-07-02 Chris Bourne , Adam Rennie

Las Vergnas and Hamidoune studied the number of circuits needed to determine an oriented matroid. In this paper we investigate this problem and some new variants, as well as their interpretation in particular classes of matroids. We present…

Combinatorics · Mathematics 2016-07-18 Kolja Knauer , Luis Pedro Montejano , Jorge Luis Ramírez Alfonsín

We provide explicit combinatorial formulas for the Chow polynomial and for the augmented Chow polynomial of uniform matroids, thereby proving a conjecture by Ferroni. These formulas refine existing formulas by Hampe and by Eur, Huh, and…

Combinatorics · Mathematics 2024-12-02 Elena Hoster

We prove that a rational linear combination of Chern numbers is an oriented diffeomorphism invariant of smooth complex projective varieties if and only if it is a linear combination of the Euler and Pontryagin numbers. In dimension at least…

Geometric Topology · Mathematics 2011-11-24 D. Kotschick
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