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Related papers: Level Planarity: Transitivity vs. Even Crossings

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In this paper we will give a unified proof of several results on the sovability of systems of certain equations over finite fields, which were recently obtained by Fourier analytic methods. Roughly speaking, we show that almost all systems…

Combinatorics · Mathematics 2009-04-03 Le Anh Vinh

We reprove the strong Hanani-Tutte theorem on the projective plane. In contrast to the previous proof by Pelsmajer, Schaefer and Stasi, our method is constructive and does not rely on the characterization of forbidden minors, which gives…

Computational Geometry · Computer Science 2016-08-31 Éric Colin de Verdière , Vojtěch Kaluža , Pavel Paták , Zuzana Patáková , Martin Tancer

Given a graph $G$, a set $T$ of terminal vertices, and a demand graph $H$ on $T$, the \textsc{Multicut} problem asks for a set of edges of minimum weight that separates the pairs of terminals specified by the edges of $H$. The…

Computational Complexity · Computer Science 2026-01-27 Florian Hörsch , Dániel Marx

The \emph{segment number} of a planar graph is the smallest number of line segments whose union represents a crossing-free straight-line drawing of the given graph in the plane. The segment number is a measure for the visual complexity of a…

Computational Geometry · Computer Science 2019-09-10 Yoshio Okamoto , Alexander Ravsky , Alexander Wolff

We provide linear-time algorithms for geometric graphs with sublinearly many crossings. That is, we provide algorithms running in O(n) time on connected geometric graphs having n vertices and k crossings, where k is smaller than n by an…

Computational Geometry · Computer Science 2010-12-16 David Eppstein , Michael T. Goodrich , Darren Strash

A graph is 1-planar if it can be drawn on a plane so that each edge is crossed by at most one other edge. In this paper, we first give a useful structural theorem for 1-planar graphs, and then apply it to the list edge and list total…

Combinatorics · Mathematics 2019-12-17 Xin Zhang , Bei Niu , Jiguo Yu

There have been researches on sufficient spectral conditions for Hamiltonian properties and path-coverable properties of graphs. Utilizing the Bondy-Chv\'atal closure, we provide a unified approach to study sufficient graph eigenvalue…

Combinatorics · Mathematics 2020-05-11 Muhuo Liu , Yang Wu , Hong-Jian Lai

We prove that if an $n$-vertex graph $G$ can be drawn in the plane such that each pair of crossing edges is independent and there is a crossing-free edge that connects their endpoints, then $G$ has $O(n)$ edges. Graphs that admit such…

Combinatorics · Mathematics 2016-08-31 Eyal Ackerman , Balázs Keszegh , Mate Vizer

We consider a \textit{PT}-symmetric cubic oscillator with an imaginary double well. We prove the existence of an infinite number of level crossings with a definite selection rule. Decreasing the positive parameter $\hbar$ from large values,…

Mathematical Physics · Physics 2016-02-17 Riccardo Giachetti , Vincenzo Grecchi

We revisit a classical paper about (even hole, triangle)-free graphs [Conforti, Cornu\'ejols, Kapoor and Vu\v skovi\'c, Triangle-free graphs that are signable without even holes, Journal of Graph Theory, 34(3), 204--220, 2000]. In fact, the…

Combinatorics · Mathematics 2026-04-03 Beatriz Martins , Nicolas Trotignon

The k-planar graphs, which are (usually with small values of k such as 1, 2, 3) subject to recent intense research, admit a drawing in which edges are allowed to cross, but each one edge is allowed to carry at most k crossings. In recently…

Combinatorics · Mathematics 2024-10-02 Petr Hliněný , Lili Ködmön

Consider property testing on bounded degree graphs and let $\varepsilon>0$ denote the proximity parameter. A remarkable theorem of Newman-Sohler (SICOMP 2013) asserts that all properties of planar graphs (more generally hyperfinite) are…

Data Structures and Algorithms · Computer Science 2024-05-10 Sabyasachi Basu , Akash Kumar , C. Seshadhri

We prove that level binomial edge ideals with regularity 2 and pseudo-Gorenstein binomial edge ideals with regularity 3 are cones, and we describe them completely. Also, we characterize level and pseudo-Gorenstein binomial edge ideals of…

Commutative Algebra · Mathematics 2023-08-11 Giancarlo Rinaldo , Rajib Sarkar

The structural parameter twin-width was introduced by Bonnet et al. in [FOCS 2020], and already this first paper included an asymptotic argument bounding the twin-width of planar graphs by a non-explicit constant. Quite recently, we have…

Combinatorics · Mathematics 2022-08-31 Petr Hliněný

It is well known that any graph admits a crossing-free straight-line drawing in $\mathbb{R}^3$ and that any planar graph admits the same even in $\mathbb{R}^2$. For a graph $G$ and $d \in \{2,3\}$, let $\rho^1_d(G)$ denote the smallest…

Computational Complexity · Computer Science 2024-03-04 Steven Chaplick , Krzysztof Fleszar , Fabian Lipp , Alexander Ravsky , Oleg Verbitsky , Alexander Wolff

Consider a host hypergraph $G$ which contains a spanning structure due to minimum degree considerations. We collect three results proving that if the edges of $G$ are sampled at the appropriate rate then the spanning structure still appears…

Combinatorics · Mathematics 2023-05-17 Huy Tuan Pham , Ashwin Sah , Mehtaab Sawhney , Michael Simkin

We consider a modified notion of planarity, in which two nations of a map are considered adjacent when they share any point of their boundaries (not necessarily an edge, as planarity requires). Such adjacencies define a map graph. We give…

Discrete Mathematics · Computer Science 2007-05-23 Zhi-Zhong Chen , Michelangelo Grigni , Christos Papadimitriou

We study random labelings of graphs conditioned on a small number (typically one or two) peaks, i.e., local maxima. We show that the boundaries of level sets of a random labeling of a square with a single peak have dimension 2, in a…

Probability · Mathematics 2017-02-24 Krzysztof Burdzy , Soumik Pal

We show that the graph of a bent function is a Salem set in an appropriate sense. We also establish a simple result that quantifies redundancies in the difference operators of a function, which applies to bent functions over fields of odd…

Combinatorics · Mathematics 2025-11-25 Robert S. Coulter , Steven Senger

An equitable coloring of a graph is a proper coloring where the sizes of any two different color classes do not differ by more than one. A graph is IC-planar if it can be drawn in the plane so that no two crossed edges have a common…

Combinatorics · Mathematics 2025-04-18 Weichan Liu