Results 41 to 50 of about 391,866 (285)
On congruence equations arising from suborbital graphs [PDF]
, 2019 In this paper we deal with congruence equations arising from suborbital graphs of the normalizer of Γ_0(m) in PSL(2,R) . We also propose a conjecture concerning the suborbital graphs of the normalizer and the related congruence equations.
Beşenk, Murat +2 more
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Graph polynomials and paintability of plane graphs
Discrete Applied Mathematics, 2022 There exists a variety of coloring problems for plane graphs, involving vertices, edges, and faces in all possible combinations. For instance, in the \emph{entire coloring} of a plane graph we are to color these three sets so that any pair of adjacent or incident elements get different colors.
Jarosław Grytczuk +2 more
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On Universal Point Sets for Planar Graphs [PDF]
, 2013 A set P of points in R^2 is n-universal, if every planar graph on n vertices admits a plane straight-line embedding on P. Answering a question by Kobourov, we show that there is no n-universal point set of size n, for any n>=15.
Cardinal, Jean +2 more
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On the Laplacian spectral radii of Halin graphs
Journal of Inequalities and Applications, 2017 Let T be a tree with at least four vertices, none of which has degree 2, embedded in the plane. A Halin graph is a plane graph constructed by connecting the leaves of T into a cycle. Thus the cycle C forms the outer face of the Halin graph, with the tree
Huicai Jia, Jie Xue
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The Degree Distribution of Thickened Trees [PDF]
Discrete Mathematics & Theoretical Computer Science, 2008 We develop a combinatorial structure to serve as model of random real world networks. Starting with plane oriented recursive trees we substitute the nodes by more complex graphs.
Michael Drmota +2 more
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Edge Partitions of Optimal $2$-plane and $3$-plane Graphs
, 2018 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 graph with a ...
CSA Nash-Williams +12 more
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On uniqueness of the q-state Potts model on a self-dual family of graphs [PDF]
, 2009 This paper deals with the location of the complex zeros of the Tutte polynomial for a class of self-dual graphs. For this class of graphs, as the form of the eigenvalues is known, the regions of the complex plane can be focused on the sets where there is
Billiot, Jean-Michel +2 more
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Aequationes Mathematicae, 1975 The orthogonality relation among subspaces of a finite vector space is studied here by means of the corresponding graph. In the case we consider, this graph has some highly symmetric induced subgraphs. We find three infinite families of graphs of girth 3, and two infinite families of graphs of girth 5, whose automorphism groups are transitive on ...
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Flat Foldings of Plane Graphs with Prescribed Angles and Edge Lengths [PDF]
, 2018 When can a plane graph with prescribed edge lengths and prescribed angles (from among $\{0,180^\circ, 360^\circ$\}) be folded flat to lie in an infinitesimally thin line, without crossings?
Abel, Zachary +5 more
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Minimal unavoidable sets of cycles in plane graphs [PDF]
Opuscula Mathematica, 2018 A set \(S\) of cycles is minimal unavoidable in a graph family \(\cal{G}\) if each graph \(G \in \cal{G}\) contains a cycle from \(S\) and, for each proper subset \(S^{\prime}\subset S\), there exists an infinite subfamily \(\cal{G}^{\prime}\subseteq\cal{
Tomáš Madaras, Martina Tamášová
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