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Related papers: Rankwidth meets stability

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We study the structure and compute the stable rank of C*-algebras of finite higher-rank graphs. We completely determine the stable rank of the C*-algebra when the k-graph either contains no cycle with an entrance, or is cofinal. We also…

Operator Algebras · Mathematics 2021-09-08 David Pask , Adam Sierakowski , Aidan Sims

Tractability results for the model checking problem of logics yield powerful algorithmic meta theorems of the form: Every computational problem expressible in a logic $L$ can be solved efficiently on every class $\mathscr{C}$ of structures…

Logic in Computer Science · Computer Science 2024-11-26 Sebastian Siebertz , Alexandre Vigny

We study the first-order model checking problem on two generalisations of pushdown graphs. The first class is the class of nested pushdown trees. The other is the class of collapsible pushdown graphs. Our main results are the following.…

Logic · Mathematics 2012-02-02 Alexander Kartzow

If for any $k$ the $k$-th coefficient of a polynomial I(G;x) is equal to the number of stable sets of cardinality $k$ in the graph $G$, then it is called the independence polynomial of $G$ (Gutman and Harary, 1983). Let $a$ be the size of a…

Combinatorics · Mathematics 2007-05-23 Vadim E. Levit , Eugen Mandrescu

The ratio of the connected domination number, $\gamma_c$, and the domination number, $\gamma$, is strictly bounded from above by 3. It was shown by Zverovich that for every connected $(P_5,C_5)$-free graph, $\gamma_c = \gamma$. In this…

Discrete Mathematics · Computer Science 2013-03-13 Eglantine Camby , Oliver Schaudt

In this paper we introduce a general framework for the study of limits of relational structures in general and graphs in particular, which is based on a combination of model theory and (functional) analysis. We show how the various…

Combinatorics · Mathematics 2021-04-23 Jaroslav Nesetril , Patrice Ossona De Mendez

We present a fixed-parameter tractable algorithm for first-order model checking on interpretations of graph classes with bounded local cliquewidth. Notably, this includes interpretations of planar graphs, and more generally, of classes of…

Data Structures and Algorithms · Computer Science 2022-03-01 Édouard Bonnet , Jan Dreier , Jakub Gajarský , Stephan Kreutzer , Nikolas Mählmann , Pierre Simon , Szymon Toruńczyk

Let $\zeta$ be Euclidean norm of the degree sequence of a graph normalized by the graph size. We prove that when the vertices of a graph are randomly colored with $s$ colors such that the fraction of vertices in each color class is bounded…

Combinatorics · Mathematics 2026-05-05 Nicola Apollonio

Let G be a finite graph with the non-k-order property (essentially, a uniform finite bound on the size of an induced sub-half-graph). A major result of the paper applies model-theoretic arguments to obtain a stronger version of…

Logic · Mathematics 2015-08-20 M. Malliaris , S. Shelah

Monadic second order logic can be used to express many classical notions of sets of vertices of a graph as for instance: dominating sets, induced matchings, perfect codes, independent sets or irredundant sets. Bounds on the number of sets…

Discrete Mathematics · Computer Science 2020-05-08 Matthieu Rosenfeld

We consider constrained variants of graph homomorphisms such as embeddings, monomorphisms, full homomorphisms, surjective homomorpshims, and locally constrained homomorphisms. We also introduce a new variation on this theme which derives…

Combinatorics · Mathematics 2014-04-23 Yangjing Long

Canonical orderings and their relatives such as st-numberings have been used as a key tool in algorithmic graph theory for the last decades. Recently, a unifying concept behind all these orders has been shown: they can be described by a…

Discrete Mathematics · Computer Science 2016-07-18 Lena Schlipf , Jens M. Schmidt

For a fixed set ${\cal H}$ of graphs, a graph $G$ is ${\cal H}$-subgraph-free if $G$ does not contain any $H \in {\cal H}$ as a (not necessarily induced) subgraph. A recently proposed framework gives a complete classification on ${\cal…

Discrete Mathematics · Computer Science 2024-05-07 Vadim Lozin , Barnaby Martin , Sukanya Pandey , Daniel Paulusma , Mark Siggers , Siani Smith , Erik Jan van Leeuwen

We consider random graphs sampled uniformly from a structured class of graphs, such as the class of graphs embeddable in a given surface. We sharpen and extend earlier results on pendant appearances, concerning for example numbers of…

Combinatorics · Mathematics 2024-05-07 Colin McDiarmid

Theory of graphical models has matured over more than three decades to provide the backbone for several classes of models that are used in a myriad of applications such as genetic mapping of diseases, credit risk evaluation, reliability and…

Machine Learning · Statistics 2014-11-13 Henrik Nyman , Johan Pensar , Timo Koski , Jukka Corander

We study connected graphs with a fixed degree sequence, in the sparse setting where the number of edges grows linearly in the number of vertices. Using the relation to the configuration model, we identify the number of such connected graphs…

Combinatorics · Mathematics 2026-05-11 Sasha Bell , Serte Donderwinkel , Remco van der Hofstad

In recent work by Johnson et al. (2022), a framework was described for the study of graph problems over classes specified by omitting each of a finite set of graphs as subgraphs. If a problem falls into the framework then its computational…

Computational Complexity · Computer Science 2025-03-17 Tala Eagling-Vose , Barnaby Martin , Daniel Paulusma , Siani Smith

High-dimensional data analysis typically focuses on low-dimensional structure, often to aid interpretation and computational efficiency. Graphical models provide a powerful methodology for learning the conditional independence structure in…

Methodology · Statistics 2024-09-13 Maria De Iorio , Willem van den Boom , Alexandros Beskos , Ajay Jasra , Andrea Cremaschi

We investigate a structural generalisation of treewidth we call $\mathcal{A}$-blind-treewidth where $\mathcal{A}$ denotes an annotated graph class. This width parameter is defined by evaluating only the size of those bags $B$ of…

Combinatorics · Mathematics 2024-10-03 J. Pascal Gollin , Sebastian Wiederrecht

The tree-independence number tree-$\alpha$, first defined and studied by Dallard, Milani\v{c} and \v{S}torgel, is a variant of treewidth tailored to solving the maximum independent set problem. Over a series of papers, Abrishami et al.…