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We present statistics on the decompositions (with respect to a distinguished symmetric 2t-cycle) of vertices of the hypercube graph, whose negative parts are regarded as disjoint unions of two subsets of the ground set {1,...,t} of the…

Combinatorics · Mathematics 2020-08-25 Andrey O. Matveev

A map graph is a graph admitting a representation in which vertices are nations on a spherical map and edges are shared curve segments or points between nations. We present an explicit fixed-parameter tractable algorithm for recognizing map…

Data Structures and Algorithms · Computer Science 2022-07-01 Patrizio Angelini , Michael A. Bekos , Giordano Da Lozzo , Martin Gronemann , Fabrizio Montecchiani , Alessandra Tappini

In many applications of autonomous mobile robots the following problem is encountered. Two maps of the same environment are available, one a prior map and the other a sensor map built by the robot. To benefit from all available information…

Robotics · Computer Science 2018-07-03 Saeed Gholami Shahbandi , Martin Magnusson

We give new decomposition theorems for classes of graphs that can be transduced in first-order logic from classes of sparse graphs -- more precisely, from classes of bounded expansion and from nowhere dense classes. In both cases, the…

Logic in Computer Science · Computer Science 2022-01-27 Jan Dreier , Jakub Gajarský , Sandra Kiefer , Michał Pilipczuk , Szymon Toruńczyk

The simple connected graphs may be classified by their cycle composition (number and lengths of cycles). This work derives the counting series of the simple connected graphs that have cycles of unrestricted number and length, but no…

Combinatorics · Mathematics 2018-08-21 Richard J. Mathar

This paper introduces a method to extract a hierarchical tree representation from 3D unorganized polygonal data. The proposed approach first extracts a graph representation of the surface, which serves as the foundation for structural…

Graphics · Computer Science 2025-10-21 Diogo de Andrade , Nuno Fachada

Bicubic maps are in bijection with \beta(0,1)-trees. We introduce two new ways of decomposing \beta(0,1)-trees. Using this we define an endofunction on \beta(0,1)-trees, and thus also on bicubic maps. We show that this endofunction is in…

Combinatorics · Mathematics 2013-06-25 Anders Claesson , Sergey Kitaev , Anna de Mier

We consider the space of embeddings of finitely many circles that bound disks in non-positively curved surfaces. We index the connected components of this space with finite rooted trees and show that the connected components are classifying…

Algebraic Topology · Mathematics 2026-01-21 Ryan C. Gelnett

Edit distances between merge trees of scalar fields have many applications in scientific visualization, such as ensemble analysis, feature tracking or symmetry detection. In this paper, we propose branch mappings, a novel approach to the…

Computational Geometry · Computer Science 2022-08-12 Florian Wetzels , Heike Leitte , Christoph Garth

We present a surprisingly new connection between two well-studied combinatorial classes: rooted connected chord diagrams on one hand, and rooted bridgeless combinatorial maps on the other hand. We describe a bijection between these two…

Combinatorics · Mathematics 2017-10-18 Julien Courtiel , Karen Yeats , Noam Zeilberger

Monotone trees - trees with a function defined on their vertices that decreases the further away from a root node one travels, are a natural model for a process that weakens the further one gets from its source. Given an aggregation of…

Data Structures and Algorithms · Computer Science 2023-09-29 Lucas Magee , Yusu Wang

It is folklore that tree-width is monotone under taking subgraphs (i.e. injective graph homomorphisms) and contractions (certain kinds of surjective graph homomorphisms). However, although tree-width is obviously not monotone under any…

Combinatorics · Mathematics 2025-06-11 Benjamin Merlin Bumpus , James Fairbanks , Will J. Turner

We consider the problem of learning the structure of undirected graphical models with bounded treewidth, within the maximum likelihood framework. This is an NP-hard problem and most approaches consider local search techniques. In this…

Machine Learning · Computer Science 2012-12-12 K. S. Sesh Kumar , Francis Bach

We show that all the tangles in a finite graph or matroid can be distinguished by a single tree-decomposition that is invariant under the automorphisms of the graph or matroid. This comes as a corollary of a similar decomposition theorem…

Combinatorics · Mathematics 2017-04-19 Reinhard Diestel , Fabian Hundertmark , Sahar Lemanczyk

A rooted planar map is a connected graph embedded in the 2-sphere, with one edge marked and assigned an orientation. A term of the pure lambda calculus is said to be linear if every variable is used exactly once, normal if it contains no…

Logic in Computer Science · Computer Science 2017-01-11 Noam Zeilberger , Alain Giorgetti

We show how to find and efficiently maintain maximal k-edge-connected subgraphs in undirected graphs. In particular, we provide the following results. (1) A general framework for maintaining the maximal k-edge-connected subgraphs upon…

Data Structures and Algorithms · Computer Science 2023-05-02 Loukas Georgiadis , Giuseppe F. Italiano , Evangelos Kosinas , Debasish Pattanayak

Given a $k$-node pattern graph $H$ and an $n$-node host graph $G$, the subgraph counting problem asks to compute the number of copies of $H$ in $G$. In this work we address the following question: can we count the copies of $H$ faster if…

Computational Complexity · Computer Science 2020-09-01 Marco Bressan

Dynamic programming is widely used for exact computations based on tree decompositions of graphs. However, the space complexity is usually exponential in the treewidth. We study the problem of designing efficient dynamic programming…

Data Structures and Algorithms · Computer Science 2014-06-16 Martin Furer , Huiwen Yu

Unrooted phylogenetic networks are graphs used to represent evolutionary relationships. Accurately reconstructing such networks is of great relevance for evolutionary biology. It has recently been conjectured that all phylogenetic networks…

Combinatorics · Mathematics 2021-01-01 Péter L. Erdős , Leo van Iersel , Mark Jones

Bauer and Itzykson showed that associated to each labeled map embedded on an oriented Riemann surface there was a group generated by a pair of permutations. From this result an algorithm may be constructed for enumerating labeled maps, and…

Combinatorics · Mathematics 2007-05-23 Virgil U. Pierce
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