English
Related papers

Related papers: Triangle-free quantum graphs

200 papers

We present an alternative approach to unveil a different kind of entanglement in bipartite quantum states whose diagonal zero patterns in suitable matrix representations admit a nice description in terms of triangle-free graphs. Upon…

Quantum Physics · Physics 2021-03-30 Satvik Singh

In this paper, we discover all the triangle-free graphs that are competition graphs of multipartite tournaments.

Combinatorics · Mathematics 2023-03-23 Myungho Choi , Minki Kwak , Suh-Ryung Kim

Consider the triangle-free graph process, which starts from the empty graph on $n$ vertices and a random ordering of the possible ${n \choose 2}$ edges; the edges are added in this ordering provided the graph remains triangle free. We will…

Combinatorics · Mathematics 2010-02-12 Stefanie Gerke , Tamás Makai

A simplified version of the theory of strongly regular graphs is developed for the case in which the graphs have no triangles. This leads to (i) direct proofs of the Krein conditions, and (ii) the characterization of strongly regular graphs…

Combinatorics · Mathematics 2009-11-12 Norman Biggs

We define several new types of quantum chromatic numbers of a graph and characterise them in terms of operator system tensor products. We establish inequalities between these chromatic numbers and other parameters of graphs studied in the…

Operator Algebras · Mathematics 2013-11-28 Vern I. Paulsen , Ivan G. Todorov

It is well known that a graph with $m$ edges can be made triangle-free by removing (slightly less than) $m/2$ edges. On the other hand, there are many classes of graphs which are hard to make triangle-free in the sense that it is necessary…

Combinatorics · Mathematics 2010-09-03 Raphael Yuster

A triangle-free graph G is called k-existentially complete if for every induced k-vertex subgraph H of G, every extension of H to a (k+1)-vertex triangle-free graph can be realized by adding another vertex of G to H. Cherlin asked whether…

Combinatorics · Mathematics 2015-08-13 Chaim Even-Zohar , Nati Linial

We generalize the enhanced power graph by replacing elements with conjugacy classes. The main result of this paper is to determine when this graph is triangle-free.

Group Theory · Mathematics 2025-03-11 Mark L. Lewis , Abbas Mohammadian

We consider the triangle-free process: given an integer n, start by taking a uniformly random ordering of the edges of the complete n-vertex graph K_n. Then, traverse the ordered edges and add each traversed edge to an (initially empty)…

Combinatorics · Mathematics 2009-07-06 Guy Wolfovitz

We conjecture that the balanced complete bipartite graph $K_{\lfloor n/2 \rfloor,\lceil n/2 \rceil}$ contains more cycles than any other $n$-vertex triangle-free graph, and we make some progress toward proving this. We give equivalent…

Combinatorics · Mathematics 2014-10-30 Stephane Durocher , David S. Gunderson , Pak Ching Li , Matthew Skala

We explore the concept of a graph homomorphism through the lens of C$^*$-algebras and operator systems. We start by studying the various notions of a quantum graph homomorphism and examine how they are related to each other. We then define…

Operator Algebras · Mathematics 2016-02-23 Carlos M. Ortiz , Vern I. Paulsen

We investigate the separability of arbitrary dimensional tripartite sys- tems. By introducing a new operator related to transformations on the subsystems a necessary condition for the separability of tripartite systems is presented.

Quantum Physics · Physics 2008-09-08 Ming Li , Shao-Ming Fei , Zhi-Xi Wang

The triangle-free process begins with an empty graph on n vertices and iteratively adds edges chosen uniformly at random subject to the constraint that no triangle is formed. We determine the asymptotic number of edges in the maximal…

Combinatorics · Mathematics 2019-09-06 Tom Bohman , Peter Keevash

Since planar triangle-free graphs are 3-colourable, such a graph with n vertices has an independent set of size at least n/3. We prove that unless the graph contains a certain obstruction, its independence number is at least n/(3-epsilon)…

Combinatorics · Mathematics 2017-02-10 Zdeněk Dvořák , Jordan Venters

We investigate the properties of different levels of entanglement in graph states which correspond to connected graphs. Combining the operational definition of graph states and the postulates of entanglement measures, we prove that in…

Quantum Physics · Physics 2008-07-11 Jian-Ming Cai , Zheng-Wei Zhou , Guang-Can Guo

Maximal $(k+1)$-crossing-free graphs on a planar point set in convex position, that is, $k$-triangulations, have received attention in recent literature, with motivation coming from several interpretations of them. We introduce a new way of…

Combinatorics · Mathematics 2012-06-14 Vincent Pilaud , Francisco Santos

It is proved that there are triangle-free intersection graphs of line segments in the plane with arbitrarily small ratio between the maximum size of an independent set and the total number of vertices.

Combinatorics · Mathematics 2014-12-30 Bartosz Walczak

In this study we consider the problem of triangulated graphs. Precisely we give a necessary and sufficient condition for a graph to be triangulated. This give an alternative characterization of triangulated graphs. Our method is based on…

Combinatorics · Mathematics 2018-11-21 R. Gargouri , H. Najar

We extend our previous algorithm that generates all labeled graphs with a given graphical degree sequence to generate all labeled triangle-free graphs with a given graphical degree sequence. The algorithm uses various pruning techniques to…

Combinatorics · Mathematics 2026-01-23 Kai Wang

We summarize different approaches to the theory of quantum graphs and provide several ways to construct concrete examples. First, we classify all undirected quantum graphs on the quantum space $M_2$. Secondly, we apply the theory of…

Quantum Algebra · Mathematics 2022-12-15 Daniel Gromada
‹ Prev 1 2 3 10 Next ›