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Related papers: Deza graphs and regular polyhedra

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We propose a classification of polyhedra (planar, $3$-connected graphs) according to their type i.e., their set of quantities of common neighbours for each pair of distinct vertices. For every (finite) set of non-negative integers, we…

Combinatorics · Mathematics 2025-08-05 Riccardo W. Maffucci

Given a polyhedron (planar, $3$-connected graph) $G$, we investigate its common neighbourhood graph con($G$). For cubic ($3$-regular) polyhedra, we show that the planarity of con($G$) depends on the number of odd faces of $G$, and on their…

Combinatorics · Mathematics 2026-05-18 Riccardo W. Maffucci

In this paper we survey existing results on Deza graphs and give some new results. We present an introduction to Deza graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of…

Combinatorics · Mathematics 2021-06-02 Sergey Goryainov , Leonid V. Shalaginov

A Deza graph with parameters $(n,k,b,a)$ is a $k$-regular graph with $n$ vertices in which any two vertices have $a$ or $b$ ($a\leq b$) common neighbours. A Deza graph is strictly Deza if it has diameter $2$, and is not strongly regular. In…

Combinatorics · Mathematics 2021-03-02 Sergey Goryainov , Willem H. Haemers , Vladislav V. Kabanov , Leonid Shalaginov

A Deza graph with parameters $(v,k,b,a)$ is a $k$-regular graph on $v$ vertices in which the number of common neighbors of two distinct vertices takes two values $a$ or $b$ ($a\leq b$) and both cases exist. In the previous papers Deza…

Combinatorics · Mathematics 2021-05-11 Vladislav Kabanov , Leonid Shalaginov

A Deza graph $\Gamma$ with parameters $(v,k,b,a)$ is a $k$-regular graph with $v$ vertices such that any two distinct vertices have $b$ or $a$ common neighbours, where $b \ge a$. A Deza graph of diameter 2 which is not a strongly regular…

Combinatorics · Mathematics 2022-10-20 Sergey Goryainov , Dmitry Panasenko , Leonid Shalaginov

For every positive integer $n$, we find a complete classification for planar graphs according to the collection of numbers of common neighbours for every $n$-tuple of distinct vertices. Our results expand the literature on planar graphical…

Combinatorics · Mathematics 2025-11-25 Riccardo W. Maffucci

A Deza graph $G$ with parameters $(n,k,b,a)$ is a $k$-regular graph with $n$ vertices such that any two distinct vertices have $b$ or $a$ common neighbours. The children $G_A$ and $G_B$ of a Deza graph $G$ are defined on the vertex set of…

We define a simple orthogonal polyhedron to be a three-dimensional polyhedron with the topology of a sphere in which three mutually-perpendicular edges meet at each vertex. By analogy to Steinitz's theorem characterizing the graphs of…

Computational Geometry · Computer Science 2016-08-12 David Eppstein , Elena Mumford

A Deza graph G with parameters (n,k,b,a) is a k-regular graph with n vertices such that any two distinct vertices have b or a common neighbours, where b >= a. The children G_A and G_B of a Deza graph G are defined on the vertex set of G…

Combinatorics · Mathematics 2021-01-19 Vladislav V. Kabanov , Elena V. Konstantinova , Leonid Shalaginov

A polyhedral graph is a $3$-connected planar graph. We find the least possible order $p(k,a)$ of a polyhedral graph containing a $k$-independent set of size $a$ for all positive integers $k$ and $a$. In the case $k = 1$ and $a$ even, we…

Combinatorics · Mathematics 2023-01-02 Sébastien Gaspoz , Riccardo W. Maffucci

A nonempty $k$-regular graph $\Gamma$ on $n$ vertices is called a Deza graph if there exist constants $b$ and $a$ $(b \geq a)$ such that any pair of distinct vertices of $\Gamma$ has precisely either $b$ or $a$ common neighbours. The…

Combinatorics · Mathematics 2021-05-11 V. V. Kabanov , N. V. Maslova , L. V. Shalaginov

In this article we present theoretical and computational results on the existence of polyhedral embeddings of graphs. The emphasis is on cubic graphs. We also describe an efficient algorithm to compute all polyhedral embeddings of a given…

Combinatorics · Mathematics 2023-06-22 Gunnar Brinkmann , Thomas Tucker , Nico Van Cleemput

Symmetric edge polytopes are lattice polytopes associated with finite simple graphs that are of interest in both theory and applications. We investigate the facet structure of symmetric edge polytopes for various models of random graphs.…

Combinatorics · Mathematics 2024-02-14 Benjamin Braun , Kaitlin Bruegge , Matthew Kahle

The only open case of Vizing's conjecture that every planar graph with $\Delta\geq 6$ is a class 1 graph is $\Delta = 6$. We give a short proof of the following statement: there is no 6-critical plane graph $G$, such that every vertex of…

Combinatorics · Mathematics 2017-02-27 Ligang Jin , Yingli Kang , Eckhard Steffen

In this note, we provide several constructions of Deza Cayley graphs over groups having a generalized dihedral subgroup. These constructions are based on a usage of (relative) difference sets.

Combinatorics · Mathematics 2026-01-15 Grigory Ryabov

The Sierpi\'nski product of graphs generalises the vast and relevant class of Sierpi\'nski-type graphs, and is also related to the classic lexicographic product of graphs. Our first main results are necessary and sufficient conditions for…

Combinatorics · Mathematics 2025-06-23 Riccardo W. Maffucci

A normally regular digraph with parameters $(v,k,\lambda,\mu)$ is a directed graph on $v$ vertices whose adjacency matrix $A$ satisfies the equation $AA^t=k I+\lambda (A+A^t)+\mu(J-I-A-A^t)$. This means that every vertex has out-degree $k$,…

Combinatorics · Mathematics 2014-10-31 Leif K Jørgensen

A classic theorem by Steinitz states that a graph G is realizable by a convex polyhedron if and only if G is 3-connected planar. Zonohedra are an important subclass of convex polyhedra having the property that the faces of a zonohedron are…

Computational Geometry · Computer Science 2008-11-04 Muhammad Abdullah Adnan , Masud Hasan

For any finite set $\A$ of $n$ points in $\R^2$, we define a $(3n-3)$-dimensional simple polyhedron whose face poset is isomorphic to the poset of ``non-crossing marked graphs'' with vertex set $\A$, where a marked graph is defined as a…

Combinatorics · Mathematics 2007-05-23 David Orden , Francisco Santos
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