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Related papers: Triangle-free quantum graphs

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In 1994, Alon construct a triangle-free $(n,d,\lambda)$-graph with $d = \Omega(n^{2/3})$ and $\lambda = O(d^{1/2})$ for an exponentially increasing sequence of integers $n$. Using his ingenious construction, we deduce that there exist…

Combinatorics · Mathematics 2024-01-05 Jaehoon Kim , Hyunwoo Lee

Quantum graphs are commonly used as models of complex quantum systems, for example molecules, networks of wires, and states of condensed matter. We consider quantum statistics for indistinguishable spinless particles on a graph,…

Mathematical Physics · Physics 2011-01-11 JM Harrison , JP Keating , JM Robbins

A wheel is a graph consisting of an induced cycle of length at least four and a single additional vertex with at least three neighbours on the cycle. We prove that no Burling graph contains an induced wheel. Burling graphs are triangle-free…

Combinatorics · Mathematics 2022-02-18 James Davies

We prove that there is an absolute constant $C>0$ so that for every natural $n$ there exists a triangle-free \emph{regular} graph with no independent set of size at least $C\sqrt{n\log n}$.

Combinatorics · Mathematics 2010-08-12 Noga Alon , Sonny Ben-Shimon , Michael Krivelevich

We formalize the correspondence between quantum states and quantum operations isometrically, and harness its consequences. This correspondence was already implicit in the various proofs of the operator sum representation of Completely…

Quantum Physics · Physics 2009-11-10 Pablo Arrighi , Christophe Patricot

A good drawing of a simple graph is a drawing on the sphere or, equivalently, in the plane in which vertices are drawn as distinct points, edges are drawn as Jordan arcs connecting their end vertices, and any pair of edges intersects at…

Computational Geometry · Computer Science 2013-06-24 Oswin Aichholzer , Thomas Hackl , Alexander Pilz , Pedro A. Ramos , Vera Sacristán , Birgit Vogtenhuber

The free scalar field is studied on the Y-junction of three semi infinite axes which is the simplest example of a non-manifold space. It is shown that under an assumption that the junction point can not gain a macroscopic amount of energy…

Quantum Physics · Physics 2008-04-01 P. N. Bibikov , L. V. Prokhorov

In this paper we initiate the study of property testing in simultaneous and non-simultaneous multi-party communication complexity, focusing on testing triangle-freeness in graphs. We consider the $\textit{coordinator}$ model, where we have…

Data Structures and Algorithms · Computer Science 2017-05-24 Orr Fischer , Shay Gershtein , Rotem Oshman

Let $G$ be a simple finite graph, and let $\mathcal U_G$ be the related quantum graph. We study the game algebra $C(\mathrm{Qut}(\mathcal U_G))$ of quantum automorphism of $\mathcal U_G$. Moreover, we prove that for any graph $G$ with…

Operator Algebras · Mathematics 2026-03-31 Olha Ostrovska , Vasyl Ostrovskyi , Lyudmila Turowska

Quantum networks with bipartite resources and shared randomness present the simplest infrastructure for implementing a future quantum internet. Here, we shall investigate which kinds of entanglement can or cannot be generated from this kind…

Quantum Physics · Physics 2025-03-13 Xiang Zhou , Zhen-Peng Xu , Liang-Liang Sun , Chunfeng Wu , Sixia Yu

In contrast to the usual quantum systems which have at most a finite number of open spectral gaps if they are periodic in more than one direction, periodic quantum graphs may have gaps arbitrarily high in the spectrum. This property of…

Quantum Physics · Physics 2020-05-26 Pavel Exner , Ondřej Turek

Given a set $F$ of oriented graphs, a graph $G$ is an $F$-graph if it admits an $F$-free orientation. Building on previous work by Bang-Jensen and Urrutia, we propose a master algorithm that determines if a graph admits an $F$-free…

Combinatorics · Mathematics 2023-01-16 Santiago Guzmán-Pro , César Hernández-Cruz

We study the typical structure and the number of triangle-free graphs with $n$ vertices and $m$ edges where $m$ is large enough so that a typical triangle-free graph has a cut containing nearly all of its edges, but may not be bipartite.…

Combinatorics · Mathematics 2025-08-14 Matthew Jenssen , Will Perkins , Aditya Potukuchi

Strictly Chordality-k graphs (SC_k graphs) are graphs which are either cycle free or every induced cycle is exactly k, for some fixed k, k \geq 3. Note that k = 3 and k = 4 are precisely the Chordal graphs and Chordal Bipartite graphs,…

Discrete Mathematics · Computer Science 2017-09-04 S. Dhanalakshmi , N. Sadagopan

One of the oldest results in modern graph theory, due to Mantel, asserts that every triangle-free graphs on $n$ vertices has at most $\lfloor n^2/4\rfloor$ edges. About half a century later Andr\'asfai studied dense triangle-free graphs and…

Combinatorics · Mathematics 2022-07-08 Tomasz Łuczak , Joanna Polcyn , Christian Reiher

In this paper, we give a polynomial time algorithm which determines if a given triangle-free graph with no induced seven-vertex path is 3-colorable, and gives an explicit coloring if one exists.

Combinatorics · Mathematics 2014-09-19 Maria Chudnovsky , Peter Maceli , Mingxian Zhong

We derive a formula for the QE constant of a complete multipartite graph and determine the complete multipartite graphs of non-QE class, namely, those which do not admit quadratic embeddings in a Euclidean space. Moreover, the primary…

Combinatorics · Mathematics 2023-11-09 Nobuaki Obata

In this research, we determine the structure of (claw, bull)-free graphs. We show that every connected (claw, bull)-free graph is either an expansion of a path, an expansion of a cycle, or the complement of a triangle-free graph; where an…

Combinatorics · Mathematics 2019-01-03 Sebastián González Hermosillo de la Maza , Yifan Jing , Masood Masjoody

Quantum computing (QC) is a new computational paradigm whose foundations relate to quantum physics. Notable progress has been made, driving the birth of a series of quantum-based algorithms that take advantage of quantum computational…

Quantum Physics · Physics 2022-02-22 Yehui Tang , Junchi Yan , Hancock Edwin

For a positive integer $k$, we say that a graph is $k$-existentially complete if for every $0 \leq a \leq k$, and every tuple of distinct vertices $x_1,\ldots,x_a$, $y_1,\ldots,y_{k-a}$, there exists a vertex $z$ that is joined to all of…

Combinatorics · Mathematics 2017-08-30 Shoham Letzter , Julian Sahasrabudhe