English
Related papers

Related papers: Monoid algebras and graph products

200 papers

The category of all monads over many-sorted sets (and over other "set-like" categories) is proved to have coequalizers and strong cointersections. And a general diagram has a colimit whenever all the monads involved preserve monomorphisms…

Logic in Computer Science · Computer Science 2014-09-15 Jiří Adámek

Coverings of undirected graphs are used in distributed computing, and unfoldings of directed graphs in semantics of programs. We study these two notions from a graph theoretical point of view so as to highlight their similarities, as they…

Logic in Computer Science · Computer Science 2026-04-08 Bruno Courcelle

We study the extended root polytope associated to a directed graph. We show that under the operations of deletion and contraction of an edge of the graph, none of the coefficients of the $h^*$-polynomial of the associated extended root…

Combinatorics · Mathematics 2025-01-10 Tamás Kálmán , Lilla Tóthmérész

We prove a deletion-contraction formula for motivic Feynman rules given by the classes of the affine graph hypersurface complement in the Grothendieck ring of varieties. We derive explicit recursions and generating series for these motivic…

Mathematical Physics · Physics 2012-04-11 Paolo Aluffi , Matilde Marcolli

We study the reverse mathematics and computability of countable graph theory, obtaining the following results. The principle that every countable graph has a connected component is equivalent to $\mathsf{ACA}_0$ over $\mathsf{RCA}_0$. The…

Logic · Mathematics 2015-08-27 Kirill Gura , Jeffry L. Hirst , Carl Mummert

Dujmovi\'c et al. [\emph{J.~ACM}~'20] recently proved that every planar graph is isomorphic to a subgraph of the strong product of a bounded treewidth graph and a path. Analogous results were obtained for graphs of bounded Euler genus or…

Combinatorics · Mathematics 2022-11-22 Vida Dujmović , Pat Morin , David R. Wood

Partially commutative monoids provide a powerful tool to study graphs, viewingwalks as words whose letters, the edges of the graph, obey a specific commutation rule. A particularclass of traces emerges from this framework, the hikes, whose…

Combinatorics · Mathematics 2017-07-18 P. -L Giscard , P Rochet

Generalizing the classical matrix-tree theorem we provide a formula counting subgraphs of a given graph with a fixed 2-core. We use this generalization to obtain an analog of the matrix-tree theorem for the root system $D_n$ (the classical…

Combinatorics · Mathematics 2007-05-23 Yurii Burman , Boris Shapiro

Let G be a graph in a 3-manifold M. We compress the pair (M,G) along admissible 2-spheres as long as possible. What we get is a root of (M,G). Our main result is that for any pair (M,G) the root exists and is unique. As a corollary we get…

Geometric Topology · Mathematics 2007-05-23 Sergei Matveev

We construct centrally large subalgebras in crossed products of $C (X, D)$ by automorphisms in which $D$ is simple, $X$ is compact metrizable, the automorphism induces a minimal homeomorphism of $X$, and a mild technical assumption holds.…

Operator Algebras · Mathematics 2020-09-28 Dawn Archey , Julian Buck , N. Christopher Phillips

Using $n$ finite order automorphisms on a simple complex Lie algebra we construct twisted $n$-toroidal Lie algebras. Thus obtaining Lie algebras wich have a rootspace decomposition. For the case $n=2$ we list certain simple Lie algebras and…

Representation Theory · Mathematics 2007-05-23 Johan van de Leur

The theory of unified product and extending structures for alternative and pre-alternative algebras are developed. It is proved that the extending structures of these algebras can be classified by using some non-abelian cohomology and…

Rings and Algebras · Mathematics 2021-08-24 Tao Zhang , Shuxian Cui , Jing Si

We undertake a comprehensive study of structural properties of graph products of von Neumann algebras equipped with faithful, normal states, as well as properties of the graph products relative to subalgebras coming from induced subgraphs.…

We prove vanishing results for Lie groups and algebraic groups (over any local field) in bounded cohomology. The main result is a vanishing below twice the rank for semi-simple groups. Related rigidity results are established for…

Group Theory · Mathematics 2012-07-10 Nicolas Monod

We study a tensor product in the category of effect algebras and in the category of partially ordered Abelian groups with order unit. We show that the tensor product preserves all the constructions that are essentially colimits over a…

Mathematical Physics · Physics 2025-03-04 Dominik Lachman

Assume that the vertices of a graph $G$ are always operational, but the edges of $G$ fail independently with probability $q \in[0,1]$. The \emph{all-terminal reliability} of $G$ is the probability that the resulting subgraph is connected.…

Combinatorics · Mathematics 2018-10-01 J. I. Brown , C. D. C. DeGagne

Given an infinite, compact, monothetic group $G$ we study decompositions and structure of unbounded derivations in a crossed product C$^*$-algebra $C(G)\rtimes\Z$ obtained from a translation on $G$ by a generator of a dense cyclic subgroup.…

Operator Algebras · Mathematics 2023-06-22 Slawomir Klimek , Matt McBride

Product structure theorems are a collection of recent results that have been used to resolve a number of longstanding open problems on planar graphs and related graph classes. One particularly useful version states that every planar graph…

Combinatorics · Mathematics 2024-06-17 Vida Dujmović , Gwenaël Joret , Piotr Micek , Pat Morin , David R. Wood

We prove the first rigidity and classification theorems for crossed product von Neumann algebras given by actions of non-discrete, locally compact groups. We prove that for arbitrary free probability measure preserving actions of connected…

Operator Algebras · Mathematics 2018-07-20 Arnaud Brothier , Tobe Deprez , Stefaan Vaes

The classical matrix tree theorem relates the number of spanning trees of a connected graph with the product of the nonzero eigenvalues of its Laplacian matrix. The class of regular matroids generalizes that of graphical matroids, and a…

Combinatorics · Mathematics 2014-05-12 Aaron Dall , Julian Pfeifle