English
Related papers

Related papers: Level Planarity: Transitivity vs. Even Crossings

200 papers

A topological graph is a graph drawn in the plane. A topological graph is $k$-plane, $k>0$, if each edge is crossed at most $k$ times. We study the problem of partitioning the edges of a $k$-plane graph such that each partite set forms a…

Study of the level curve for the real part of $\eta(s)=0$ with $\eta(s)=\pi^{-s/2}\Gamma(s/2)\zeta^\prime(s)$ gives a new classification of the zeros of $\zeta(s)$ and of $\zeta^\prime(s)$. We conjecture that for type 2 zeros, $\liminf…

Number Theory · Mathematics 2025-03-12 Jeffrey Stopple

The conventional duality analysis is employed to identify a location of a critical point on a uniform lattice without any disorder in its structure. In the present study, we deal with the random planar lattice, which consists of the…

Disordered Systems and Neural Networks · Physics 2015-06-11 Masayuki Ohzeki , Keisuke Fujii

We initiate the study of Simultaneous Graph Embedding with Fixed Edges in the beyond planarity framework. In the QuaSEFE problem, we allow edge crossings, as long as each graph individually is drawn quasiplanar, that is, no three edges…

Data Structures and Algorithms · Computer Science 2019-08-26 Patrizio Angelini , Henry Förster , Michael Hoffmann , Michael Kaufmann , Stephen Kobourov , Giuseppe Liotta , Maurizio Patrignani

Beyond planarity concepts (prominent examples include k-planarity or fan-planarity) apply certain restrictions on the allowed patterns of crossings in drawings. It is natural to ask, how much the number of crossings may increase over the…

Computational Geometry · Computer Science 2024-09-05 Markus Chimani , Torben Donzelmann , Nick Kloster , Melissa Koch , Jan-Jakob Völlering , Mirko H. Wagner

We show that a discrete harmonic function which is bounded on a large portion of a periodic planar graph is constant. A key ingredient is a new unique continuation result for the weighted graph Laplacian. The proof relies on the structure…

Analysis of PDEs · Mathematics 2025-09-11 Ahmed Bou-Rabee , William Cooperman , Shirshendu Ganguly

A graph G is called "minimalizable" if a diagram with minimal crossing number can be obtained from an arbitrary diagram of G by crossing changes. If, furthermore, the minimal diagram is unique up to crossing changes then G is called…

Geometric Topology · Mathematics 2007-05-23 J. Sawollek

Two-sample hypothesis testing for random graphs arises naturally in neuroscience, social networks, and machine learning. In this paper, we consider a semiparametric problem of two-sample hypothesis testing for a class of latent position…

Methodology · Statistics 2015-06-19 Minh Tang , Avanti Athreya , Daniel L. Sussman , Vince Lyzinski , Carey E. Priebe

We present a data structure that can maintain a simple planar graph under edge contractions in linear total time. The data structure supports adjacency queries and provides access to neighbor lists in $O(1)$ time. Moreover, it can report…

Data Structures and Algorithms · Computer Science 2017-07-03 Jacob Holm , Giuseppe F. Italiano , Adam Karczmarz , Jakub Łącki , Eva Rotenberg , Piotr Sankowski

Two-sample tests utilizing a similarity graph on observations are useful for high-dimensional and non-Euclidean data due to their flexibility and good performance under a wide range of alternatives. Existing works mainly focused on sparse…

Statistics Theory · Mathematics 2023-11-14 Yejiong Zhu , Hao Chen

We present parity conditions under which a toy rail network is one-way, i.e., whether a direction can be assigned across the network so that all train journeys are completely consistent with it or completely consistent with its opposite. We…

Combinatorics · Mathematics 2025-09-16 Dai Akita , Daniel Thorsten Schenz

The Graph Isomorphism problem has both theoretical and practical interest. In this paper we present an algorithm, called conauto-1.2, that efficiently tests whether two graphs are isomorphic, and finds an isomorphism if they are. This…

Data Structures and Algorithms · Computer Science 2011-06-23 Jose Luis Lopez-Presa , Antonio Fernandez Anta

In this paper we deepen the understanding of the connection between two long-standing Graph Drawing open problems, that is, Simultaneous Embedding with Fixed Edges (SEFE) and Clustered Planarity (C-PLANARITY). In his GD'12 paper Marcus…

Computational Complexity · Computer Science 2014-04-25 Patrizio Angelini , Giordano Da Lozzo

In this article bipartite planar graphs St_r are investigated, r the number of their plane regions. Bounds for the graded Betti numbers and the projective dimension of the quotient ring associated to such graphs are discussed. We prove that…

Commutative Algebra · Mathematics 2024-04-01 Maurizio Imbesi , Monica La Barbiera

Recently, Man\v{c}inska and Roberson proved that two graphs $G$ and $G'$ are quantum isomorphic if and only if they admit the same number of homomorphisms from all planar graphs. We extend this result to planar #CSP with any pair of sets…

Discrete Mathematics · Computer Science 2025-09-16 Jin-Yi Cai , Ben Young

Let k be an algebraically closed field of characteristic p different from 2, and let F be a nodal surface of degree d in the projective 3-space P over k (i.e. the singularities of F are only ordinary quadratic, nodes for short). Let N be a…

alg-geom · Mathematics 2008-02-03 Gianfranco Casnati , Fabrizio Catanese

We introduce a strengthening of the notion of transience for planar maps in order to relax the standard condition of bounded degree appearing in various results, in particular, the existence of Dirichlet harmonic functions proved by…

Combinatorics · Mathematics 2020-04-08 Johannes Carmesin , Agelos Georgakopoulos

We show how to test in linear time whether an outerplanar graph admits a planar rectilinear drawing, both if the graph has a prescribed plane embedding that the drawing has to respect and if it does not. Our algorithm returns a planar…

Data Structures and Algorithms · Computer Science 2020-08-24 Fabrizio Frati

Many combinatorial problems can be solved in time $O^*(c^{tw})$ on graphs of treewidth $tw$, for a problem-specific constant $c$. In several cases, matching upper and lower bounds on $c$ are known based on the Strong Exponential Time…

Computational Complexity · Computer Science 2018-06-28 Bas A. M. van Geffen , Bart M. P. Jansen , Arnoud A. W. M. de Kroon , Rolf Morel

We exhibit planar, rational curves of large degree over ${\mathbb F}_2$ that have a unique singular point, which has multiplicity 2. In characteristic 0 such curves exist only for degrees up to $6$. v.2: references updated and examples of…

Algebraic Geometry · Mathematics 2026-04-21 János Kollár