English
Related papers

Related papers: The Quad-$C_5$ Graph: Maximum Contextuality Gap on…

200 papers

$\Theta_6$-Graphs graphs are important geometric graphs that have many applications especially in wireless sensor networks. They are equivalent to Delaunay graphs where empty equilateral triangles take the place of empty circles. We…

Computational Geometry · Computer Science 2019-03-13 Therese Biedl , Ahmad Biniaz , Veronika Irvine , Kshitij Jain , Philipp Kindermann , Anna Lubiw

We propose an efficient $\epsilon$-differentially private algorithm, that given a simple {\em weighted} $n$-vertex, $m$-edge graph $G$ with a \emph{maximum unweighted} degree $\Delta(G) \leq n-1$, outputs a synthetic graph which…

Data Structures and Algorithms · Computer Science 2023-10-02 Jingcheng Liu , Jalaj Upadhyay , Zongrui Zou

In 2010, Mkrtchyan, Petrosyan and Vardanyan proved that every graph $G$ with $2\leq \delta(G)\leq \Delta(G)\leq 3$ contains a maximum matching whose unsaturated vertices do not have a common neighbor, where $\Delta(G)$ and $\delta(G)$…

Combinatorics · Mathematics 2012-08-13 Petros A. Petrosyan

The Chen-Lih-Wu Conjecture states that each connected graph with maximum degree $\Delta\geq 3$ that is not the complete graph $K_{\Delta+1}$ or the complete bipartite graph $K_{\Delta,\Delta}$ admits an equitable coloring with $\Delta$…

Combinatorics · Mathematics 2023-11-14 Alexandr Kostochka , Duo Lin , Zimu Xiang

A fundamental problem in quantum computation and quantum information is finding the minimum quantum dimension needed for a task. For tasks involving state preparation and measurements, this problem can be addressed using only the…

Quantum Physics · Physics 2022-07-19 Maharshi Ray , Naresh Goud Boddu , Kishor Bharti , Leong-Chuan Kwek , Adán Cabello

Two graphs are said to be $Q$-cospectral if they share the same signless Laplacian spectrum. A simple graph is said to be determined by its signless Laplacian spectrum (abbreviated as DQS) if there exists no other non-isomorphic simple…

Combinatorics · Mathematics 2025-10-01 Jiachang Ye , Jianguo Qian , Zoran Stanic

A cograph is a simple graph which contains no path on 4 vertices as an induced subgraph. We consider the eigenvalues of adjacency matrices of cographs and prove that a graph $G$ is a cograph if and only if no induced subgraph of $G$ has an…

Combinatorics · Mathematics 2018-10-01 Ebrahim Ghorbani

A rectangle visibility graph (RVG) is represented by assigning to each vertex a rectangle in the plane with horizontal and vertical sides in such a way that edges in the graph correspond to unobstructed horizontal and vertical lines of…

Combinatorics · Mathematics 2022-08-29 John S. Caughman , Charles L. Dunn , Joshua D. Laison , Nancy Ann Neudauer , Colin L. Starr

The {\em square} of a graph $G$, denoted $G^2$, has the same vertex set as $G$ and an edge between any two vertices at distance at most $2$ in $G$. Wegner (1977) conjectured that for a planar graph $G$, $\chi(G^2) \leq 7$ if $\Delta(G) =…

Combinatorics · Mathematics 2025-12-12 Seog-Jin Kim , Rong Luo

This paper examines the spectral characterizations of oriented graphs. Let $\Sigma$ be an $n$-vertex oriented graph with skew-adjacency matrix $S$. Previous research mainly focused on self-converse oriented graphs, proposing arithmetic…

Combinatorics · Mathematics 2025-04-28 Limeng Lin , Wei Wang , Hao Zhang

Correlations in Bell and noncontextuality inequalities can be expressed as a positive linear combination of probabilities of events. Exclusive events can be represented as adjacent vertices of a graph, so correlations can be associated to a…

Quantum Physics · Physics 2014-01-30 Adan Cabello , Simone Severini , Andreas Winter

Measurement based quantum computing is preformed by adding non-Clifford measurements to a prepared stabilizer states. Entangling gates like CZ are likely to have lower fidelities due to the nature of interacting qubits, so when preparing a…

Quantum Physics · Physics 2025-07-29 James Davies , Andrew Jena

A cubic graph $G$ is cyclically 5-connected if $G$ is simple, 3-connected, has at least 10 vertices and for every set $F$ of edges of size at most four, at most one component of $G\backslash F$ contains circuits. We prove that if $G$ and…

Combinatorics · Mathematics 2019-05-23 Neil Robertson , P. D. Seymour , Robin Thomas

We describe a construction that maps any connected graph G on three or more vertices into a larger graph, H(G), whose independence number is strictly smaller than its Lov\'asz number which is equal to its fractional packing number. The…

Quantum Physics · Physics 2013-07-19 Adan Cabello , Matthew G. Parker , Giannicola Scarpa , Simone Severini

Let $G$ be a contraction critically quasi $5$-connected graph on at least $14$ vertices. If there is a vertex $x\in V_{4}(G)$ such that $G[N_{G}(x)]\cong K_{1,3}$ or $G[N_{G}(x)]\cong C_{4}$, then $G$ has a quasi $5$-contractible subgraph…

Combinatorics · Mathematics 2022-07-27 Shuai Kou , Chengfu Qin , Weihua Yang

We consider a relaxation of the concept of well-covered graphs, which are graphs with all maximal independent sets of the same size. The extent to which a graph fails to be well-covered can be measured by its independence gap, defined as…

Discrete Mathematics · Computer Science 2023-06-22 Tınaz Ekim , Didem Gözüpek , Ademir Hujdurović , Martin Milanič

For $k \geq 1$ and a graph $G$ let $\nu_k(G)$ denote the size of a maximum $k$-edge-colorable subgraph of $G$. Mkrtchyan, Petrosyan and Vardanyan proved that $\nu_2(G)\geq \frac45\cdot |V(G)|$, $\nu_3(G)\geq \frac76\cdot |V(G)|$ for any…

Discrete Mathematics · Computer Science 2025-11-18 Lianna Hambardzumyan , Vahan Mkrtchyan

Let G be a bridgeless cubic graph. A well-known conjecture of Berge and Fulkerson can be stated as follows: there exist five perfect matchings of G such that each edge of G is contained in at least one of them. Here, we prove that in each…

Combinatorics · Mathematics 2013-06-06 Giuseppe Mazzuoccolo

In this paper, we study a conjecture of Andries E. Brouwer from 1996 regarding the minimum number of vertices of a strongly regular graph whose removal disconnects the graph into non-singleton components. We show that strongly regular…

Combinatorics · Mathematics 2012-01-12 Sebastian M. Cioaba , Kijung Kim , Jack H. Koolen

The \emph{local boxicity} of a graph $G$, denoted by $lbox(G)$, is the minimum positive integer $l$ such that $G$ can be obtained using the intersection of $k$ (, where $k \geq l$,) interval graphs where each vertex of $G$ appears as a…

Combinatorics · Mathematics 2022-01-26 Atrayee Majumder , Rogers Mathew