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We define a graded graph, called the Schur--Weyl graph, which arises naturally when one considers simultaneously the RSK algorithm and the classical duality between representations of the symmetric and general linear groups. As one of the…

Representation Theory · Mathematics 2021-07-20 A. Vershik , N. Tsilevich

We introduce two coproducts on mixed graphs (that is to say graphs with both oriented and unoriented edges), the first one by separation of the vertices into two parts, and the second one given by contraction and extractions of subgraphs.…

Combinatorics · Mathematics 2024-09-24 Loïc Foissy

The bivariate chromatic polynomial $\chi_G(x,y)$ of a graph $G = (V, E)$, introduced by Dohmen-P\"{o}nitz-Tittmann (2003), counts all $x$-colorings of $G$ such that adjacent vertices get different colors if they are $\le y$. We extend this…

Combinatorics · Mathematics 2024-02-14 Matthias Beck , Sampada Kolhatkar

We revisit a well-known family of polynomial ideals encoding the problem of graph-$k$-colorability. Our paper describes how the inherent combinatorial structure of the ideals implies several interesting algebraic properties. Specifically,…

Symbolic Computation · Computer Science 2014-10-28 Jesús A. De Loera , Susan Margulies , Michael Pernpeintner , Eric Riedl , David Rolnick , Gwen Spencer , Despina Stasi , Jon Swenson

Let $G = (V,E)$ be a finite, simple, connected graph with chromatic polynomial $P_G(q)$. Sokal \cite{sokal} proved that the roots of the chromatic polynomial of $G$ are bounded in absolute value by $KD$ where, $D$ is the maximum degree of…

Combinatorics · Mathematics 2015-09-22 Sukhada Fadnavis

Higher order cohomology of arithmetic groups is expressed in terms of (g,K)-cohomology. Generalizing results of Borel, it is shown that the latter can be computed using functions of (uniform) moderate growth. A higher order versions of…

Number Theory · Mathematics 2008-05-16 Anton Deitmar

We study character varieties arising as moduli of representations of an orientable surface group into a reductive group $G$. We first show that if $G/Z$ acts freely on the representation variety, then both the representation variety and the…

Representation Theory · Mathematics 2025-02-12 Masoud Kamgarpour , GyeongHyeon Nam , Anna Puskás

Each graph and choice of a commutative ring gives rise to an associated graphical group. In this article, we introduce and investigate graph polynomials that enumerate conjugacy classes of graphical groups over finite fields according to…

Group Theory · Mathematics 2022-03-14 Tobias Rossmann

For each positive integer n, Khovanov and Rozansky constructed an invariant of links in the form of a doubly-graded cohomology theory whose Euler characteristic is the sl(n) link polynomial. We use Lagrangian Floer cohomology on some…

Symplectic Geometry · Mathematics 2007-05-23 Ciprian Manolescu

It is known that given a directed graph E and a subset X of vertices, the sum of the projections associated to the vertices in X in the C*-algebra of E converges strictly in the multiplier algebra to a projection P. Here we give a…

Operator Algebras · Mathematics 2013-01-04 Tyrone Crisp

We give a homological interpretation of the coefficients of the Hilbert series for an algebra associated with a directed graph and its dual algebra. This allows us to obtain necessary conditions for Koszulity of such algebras in terms of…

Rings and Algebras · Mathematics 2011-11-15 Vladimir Retakh , Shirlei Serconek , Robert Wilson

The theory of path homology for digraphs was developed by Alexander Grigor'yan, Yong Lin, Yuri Muranov, and Shing-Tung Yau. In this paper, we consider the differential algebras on digraphs and define the parametrized homology of digraphs as…

Combinatorics · Mathematics 2023-05-17 Shiquan Ren , Chong Wang

We discuss the cohomology of the bridgeless graph complex, that is, the subcomplex of the Kontsevich graph complex spanned by bridgeless graphs.

Quantum Algebra · Mathematics 2025-03-26 Thomas Willwacher

We prove that every (possibly infinite) graph of degree at most $d$ has a 4-dependent random proper $4^{d(d+1)/2}$-coloring, and one can construct it as a finitary factor of iid. For unimodular transitive (or unimodular random) graphs we…

Probability · Mathematics 2024-02-28 Ádám Timár

This note proves that every graph of Euler genus $\mu$ is $\lceil 2 + \sqrt{3\mu + 3}\,\rceil$--choosable with defect 1 (that is, clustering 2). Thus, allowing defect as small as 1 reduces the choice number of surface embeddable graphs…

Discrete Mathematics · Computer Science 2018-06-19 Vida Dujmović , Djedjiga Outioua

A Koszul duality-type correspondence between coderived categories of conilpotent differential graded Lie coalgebras and their Chevalley-Eilenberg differential graded algebras is established. This gives an interpretation of Lie coalgebra…

K-Theory and Homology · Mathematics 2024-11-06 Joseph Chuang , Andrey Lazarev , Yunhe Sheng , Rong Tang

We study a family of subrings, indexed by the natural numbers, of the mod-p cohomology of a finite group G. These subrings are based on a family of v_n-periodic complex oriented cohomology theories and are constructed as rings of…

Algebraic Topology · Mathematics 2015-02-23 David J. Green , John R. Hunton , Bjoern Schuster

Suppose a graph has no large balanced bicliques, but has large minimum degree. Then what can we say about its induced subgraphs? This question motivates the study of degree-boundedness, which is like $\chi$-boundedness but for minimum…

Combinatorics · Mathematics 2024-11-14 Xiying Du , Rose McCarty

In this paper we will prove that there exists a covariant functor from the category of schemes to the category of graphs. This functor provides a combination between algebraic varieties and combinatorial graphs so that the invariants…

Algebraic Geometry · Mathematics 2009-07-06 Feng-Wen An

The dual Kontsevich cycles in the double dual of associative graph homology correspond to polynomials in the Miller-Morita-Mumford classes in the integral cohomology of mapping class groups. I explain how the coefficients of these…

Algebraic Topology · Mathematics 2007-05-23 Kiyoshi Igusa
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