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Related papers: Equivariant log-concavity of graph matchings

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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 prove a Lefschetz formula for general simple graphs which equates the Lefschetz number L(T) of an endomorphism T with the sum of the degrees i(x) of simplices in G which are fixed by T. The degree i(x) of x with respect to T is defined…

Dynamical Systems · Mathematics 2012-06-06 Oliver Knill

In the standard category of directed graphs, graph morphisms map edges to edges. By allowing graph morphisms to map edges to finite paths (path homomorphisms of graphs), we obtain an ambient category in which we determine subcategories…

Rings and Algebras · Mathematics 2024-12-20 Piotr M. Hajac , Mariusz Tobolski

For Hamiltonian circle actions on compact, connected, four-dimensional manifolds, we give a generators and relations description for the even part of the equivariant cohomology, as an algebra over the equivariant cohomology of a point. This…

Symplectic Geometry · Mathematics 2025-08-13 Tara Holm , Liat Kessler

We show that the graded Grothendieck group classifies unital Leavitt path algebras of primitive graphs up to graded homotopy equivalence. To this end, we further develop classification techniques for Leavitt path algebras by means of…

K-Theory and Homology · Mathematics 2023-09-13 Guido Arnone

In a recent paper, the first author proved the log-concavity of the coefficients of the characteristic polynomial of a matroid realizable over a field of characteristic 0, answering a long-standing conjecture of Read in graph theory. We…

Combinatorics · Mathematics 2012-02-16 June Huh , Eric Katz

Motivated by Stanley's generalization of the chromatic polynomial of a graph to the chromatic symmetric function, we introduce the characteristic polynomial of a representation of the symmetric group, or more generally, of a symmetric…

Algebraic Geometry · Mathematics 2025-11-05 Jinwon Choi , Young-Hoon Kiem , Donggun Lee

This paper is an attempt to show that, parallel to Elliott's classification of AF $C^*$-algebras by means of $K$-theory, the graded $K_0$-group classifies Leavitt path algebras completely. In this direction, we prove this claim at two…

Rings and Algebras · Mathematics 2011-11-02 R. Hazrat

We prove a Grothendieck-Lefschetz theorem for equivariant Picard groups of non-singular varieties with finite group actions.

Algebraic Geometry · Mathematics 2017-12-22 Charanya Ravi

We formulate conditions on a set of log-concave sequences, under which any linear combination of those sequences is log-concave, and further, of conditions under which linear combinations of log-concave sequences that have been transformed…

Combinatorics · Mathematics 2014-07-24 Jonathan L. Gross , Toufik Mansour , Thomas W. Tucker , David G. L. Wang

We prove that a unital shift equivalence induces a graded isomorphism of Leavitt path algebras when the shift equivalence satisfies an alignment condition. This yields another step towards confirming the Graded Classification Conjecture.…

Rings and Algebras · Mathematics 2024-09-17 Kevin Aguyar Brix , Adam Dor-On , Roozbeh Hazrat , Efren Ruiz

In this paper we address the graph matching problem. Following the recent works of \cite{zaslavskiy2009path,Vestner2017} we analyze and generalize the idea of concave relaxations. We introduce the concepts of conditionally concave and…

Optimization and Control · Mathematics 2018-12-27 Haggai Maron , Yaron Lipman

In this work we obtain the general form of polynomial mappings that commute with a linear action of a relative symmetry group. The aim is to give results for relative equivariant polynomials that correspond to the results for relative…

Dynamical Systems · Mathematics 2014-11-25 Patricia Hernandes Baptistelli , Miriam Manoel

We continue to investigate branching systems of directed graphs and their connections with graph algebras. We give a sufficient condition under which the representation induced from a branching system of a directed graph is faithful and…

Operator Algebras · Mathematics 2019-08-15 Daniel Gonçalves , Hui Li , Danilo Royer

Let G be a connected reductive algebraic group over a perfect field. We study the representability of the equivariant automorphism group of G-varieties. For a broad class of complexity-one G-varieties, we show that this group is…

Algebraic Geometry · Mathematics 2026-02-09 Giancarlo Lucchini Arteche , Ronan Terpereau

We present a combinatorial isomorphism between Stasheff associahedra and an inductive cone construction of those complexes given by Loday. We give an alternate description of certain polytopes, known as multiplihedra, which arise in the…

Combinatorics · Mathematics 2025-11-25 Somnath Basu , Sandip Samanta

The invariance to permutations of the adjacency matrix, i.e., graph isomorphism, is an overarching requirement for Graph Neural Networks (GNNs). Conventionally, this prerequisite can be satisfied by the invariant operations over node…

Machine Learning · Computer Science 2022-05-31 Zhongyu Huang , Yingheng Wang , Chaozhuo Li , Huiguang He

We consider {\em L-graphs}, that is contact graphs of axis-aligned L-shapes in the plane, all with the same rotation. We provide several characterizations of L-graphs, drawing connections to Schnyder realizers and canonical orders of…

Computational Geometry · Computer Science 2013-03-07 Steven Chaplick , Stephen Kobourov , Torsten Ueckerdt

These notes concern aspects of various graphs whose vertex set is a group $G$ and whose edges reflect group structure in some way (so that they are invariant under the action of the automorphism group of $G$). The graphs I will discuss are…

Group Theory · Mathematics 2021-03-29 Peter J. Cameron

We introduce a homological Lefschetz conjecture on (rational) Chow groups, which can be deduced from some well known conjectures, and illustrate it by a series of key examples. We then prove the injectivity of the push-forward morphism on…

Algebraic Geometry · Mathematics 2021-03-31 Kalyan Banerjee , Jaya NN Iyer , James D. Lewis