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Related papers: Triangle-free quantum graphs

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We give an exact characterization of 3-colorability of triangle-free graphs drawn in the torus, in the form of 186 "templates" (graphs with certain faces filled by arbitrary quadrangulations) such that a graph from this class is not…

Combinatorics · Mathematics 2020-09-03 Zdeněk Dvořák , Jakub Pekárek

We begin with the characterization of quantum graphs as left ideals in $\mathcal M \otimes_{eh} \mathcal M$ (the extended Haagerup tensor product of $\mathcal M$ with itself) to avoid technicalities surrounding representation dependence of…

Operator Algebras · Mathematics 2026-05-14 Jennifer Zhu

There are four non-isomorphic configurations of triples that can form a triangle in a $3$-uniform hypergraph. Forbidding different combinations of these four configurations, fifteen extremal problems can be defined, several of which already…

Combinatorics · Mathematics 2024-05-28 Peter Frankl , Zoltán Füredi , Ido Goorevitch , Ron Holzman , Gábor Simonyi

A number of famous results about triangle-free graphs determine the maximum chromatic number of graphs of order n with minimum degree greater than n/3. In this note these results are extended to Kr-free graphs.

Combinatorics · Mathematics 2010-01-14 Vladimir Nikiforov

The connection between certain entangled states and graphs has been heavily studied in the context of measurement-based quantum computation as a tool for understanding entanglement. Here we show that this correspondence can be harnessed in…

Quantum Physics · Physics 2016-03-23 Liming Zhao , Carlos A. Pérez-Delgado , Joseph F. Fitzsimons

We introduce quantum association schemes. This allows to define distance regular and strongly regular quantum graphs. We bring examples thereof. In addition, we formulate the duality for translation quantum association schemes corresponding…

Quantum Algebra · Mathematics 2026-02-10 Daniel Gromada

A quantum graph $\mathcal{G}$ housed by a matrix algebra $M_n$ can be encoded as an operator system $\mathcal S=\mathcal{S}_{\mathcal{G}}\le M_n$. There are two sensible notions of quantum automorphism group for any such:…

Quantum Algebra · Mathematics 2025-11-18 Alexandru Chirvasitu , Piotr M. Sołtan , Mateusz Wasilewski

Quantum networks allow in principle for completely novel forms of quantum correlations. In particular, quantum nonlocality can be demonstrated here without the need of having various input settings, but only by considering the joint…

The triangle graph of a graph $G$, denoted by ${\cal T}(G)$, is the graph whose vertices represent the triangles ($K_3$ subgraphs) of $G$, and two vertices of ${\cal T}(G)$ are adjacent if and only if the corresponding triangles share an…

Combinatorics · Mathematics 2015-10-20 Aparna Lakshmanan S. , Csilla Bujtás , Zsolt Tuza

Recently, settling a question of Erd\H{o}s, Balogh and Pet\v{r}\'{i}\v{c}kov\'{a} showed that there are at most $2^{n^2/8+o(n^2)}$ $n$-vertex maximal triangle-free graphs, matching the previously known lower bound. Here we characterize the…

Combinatorics · Mathematics 2016-08-07 József Balogh , Hong Liu , Šárka Petříčková , Maryam Sharifzadeh

Graph structures are ubiquitous throughout the natural sciences. Here we consider graph-structured quantum data and describe how to carry out its quantum machine learning via quantum neural networks. In particular, we consider training data…

Quantum Physics · Physics 2021-03-22 Kerstin Beer , Megha Khosla , Julius Köhler , Tobias J. Osborne

One of the apparent advantages of quantum computers over their classical counterparts is their ability to efficiently contract tensor networks. In this article, we study some implications of this fact in the case of topological tensor…

Quantum Physics · Physics 2016-10-17 Gorjan Alagic , Edgar A. Bering

Quantum entanglement in multipartite systems cannot be shared freely. In order to illuminate basic rules of entanglement sharing between qubits we introduce a concept of an entangled structure (graph) such that each qubit of a multipartite…

Quantum Physics · Physics 2009-11-07 Martin Plesch , Vladimir Buzek

Paul Erd\H{o}s suggested the following problem: Determine or estimate the number of maximal triangle-free graphs on $n$ vertices. Here we show that the number of maximal triangle-free graphs is at most $2^{n^2/8+o(n^2)}$, which matches the…

Combinatorics · Mathematics 2014-09-30 József Balogh , Šárka Petříčková

We graph-theoretically characterize triangle-free Gorenstein graphs $G$. As an application, we classify when $I(G)^2$ is Cohen-Macaulay.

Commutative Algebra · Mathematics 2015-09-01 Do Trong Hoang , Tran Nam Trung

The generation of a random triangle-saturated graph via the triangle-free process has been studied extensively. In this short note our aim is to introduce an analogous process in the hypercube. Specifically, we consider the $Q_2$-free…

Combinatorics · Mathematics 2020-10-14 J. Robert Johnson , Trevor Pinto

We present two new quantum algorithms that either find a triangle (a copy of $K_{3}$) in an undirected graph $G$ on $n$ nodes, or reject if $G$ is triangle free. The first algorithm uses combinatorial ideas with Grover Search and makes…

Quantum Physics · Physics 2007-05-23 Frederic Magniez , Miklos Santha , Mario Szegedy

We introduce a new approach and prove that the maximum number of triangles in a $C_5$-free graph on $n$ vertices is at most $$(1 + o(1)) \frac{1}{3 \sqrt 2} n^{3/2}.$$ We also show a connection to $r$-uniform hypergraphs without (Berge)…

Combinatorics · Mathematics 2018-11-30 Beka Ergemlidze , Abhishek Methuku

We revisit a classical paper about (even hole, triangle)-free graphs [Conforti, Cornu\'ejols, Kapoor and Vu\v skovi\'c, Triangle-free graphs that are signable without even holes, Journal of Graph Theory, 34(3), 204--220, 2000]. In fact, the…

Combinatorics · Mathematics 2026-04-03 Beatriz Martins , Nicolas Trotignon

It is shown that for $n\geq 141$, among all triangle-free graphs on $n$ vertices, the complete equibipartite graph is the unique triangle-free graph with the greatest number of cycles.

Combinatorics · Mathematics 2015-03-24 Andrii Arman , David S. Gunderson , Sergei Tsaturian