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An explicit algorithm is presented for testing whether two non-directed graphs are isomorphic or not. It is shown that for a graph of n vertices, the number of n independent operations needed for the test is polynomial in n. A proof that…

Data Structures and Algorithms · Computer Science 2007-05-23 Moshe Schwartz

Let $G$ be a graph whose edges are each assigned one of the $m$-colours $1, 2, \ldots, m$, and let $\Gamma$ be a subgroup of $S_m$. The operation of switching at a vertex $x$ with respect $\pi \in \Gamma$ permutes the colours of the edges…

Combinatorics · Mathematics 2022-07-27 Chris Duffy , Gary MacGillivray , Ben Tremblay

Switching about a vertex in a digraph means to reverse the direction of every edge incident with that vertex. Bondy and Mercier introduced the problem of whether a digraph can be reconstructed up to isomorphism from the multiset of…

Combinatorics · Mathematics 2013-08-06 Brendan D. McKay , Pascal Schweitzer

A graph is called a chain graph if it is bipartite and the neighborhoods of the vertices in each color class form a chain with respect to inclusion. A threshold graph can be obtained from a chain graph by making adjacent all pairs of…

Combinatorics · Mathematics 2018-03-02 M. Anđelić , E. Ghorbani , S. K. Simić

Assumed to be undirected, simple, and connected are all of the graphs in this study, and adjacency matrix $A$ serves as the associated matrix. In this paper we show that it is possible to relate a creation sequence for a type of cographs…

Combinatorics · Mathematics 2025-01-09 Santanu Mandal , Ranjit Mehatari

A homomorphism from a graph $X$ to a graph $Y$ is an adjacency preserving mapping $f:V(X) \rightarrow V(Y)$. We consider a nonlocal game in which Alice and Bob are trying to convince a verifier with certainty that a graph $X$ admits a…

Quantum Physics · Physics 2016-09-21 Laura Mančinska , David E. Roberson

Cycle switching is a particular form of transformation applied to isomorphism classes of a Steiner triple system of a given order $v$ (an $STS(v)$), yielding another $STS(v)$. This relationship may be represented by an undirected graph. An…

Combinatorics · Mathematics 2024-05-14 Grahame Erskine , Terry S. Griggs

We investigate spectral properties of quantum graphs in the form of a periodic chain of rings with a connecting link between each adjacent pair, assuming that wave functions at the vertices are matched through conditions manifestly…

Mathematical Physics · Physics 2022-07-12 Marzieh Baradaran , Pavel Exner , Milos Tater

Image hashing is the process of associating a short vector of bits to an image. The resulting summaries are useful in many applications including image indexing, image authentication and pattern recognition. These hashes need to be…

Computer Vision and Pattern Recognition · Computer Science 2010-09-17 Maxime Taquet , Laurent Jacques , Christophe De Vleeschouwer , Benoit Macq

Many applications in network analysis require algorithms to sample uniformly at random from the set of all graphs with a prescribed degree sequence. We present a Markov chain based approach which converges to the uniform distribution of all…

Discrete Mathematics · Computer Science 2010-03-05 Annabell Berger , Matthias Müller-Hannemann

Quantification learning is the task of predicting the label distribution of a set of instances. We study this problem in the context of graph-structured data, where the instances are vertices. Previously, this problem has only been…

Machine Learning · Computer Science 2026-01-01 Clemens Damke , Eyke Hüllermeier

Graph isomorphism is a problem for which there is no known polynomial-time solution. Nevertheless, assessing (dis)similarity between two or more networks is a key task in many areas, such as image recognition, biology, chemistry, computer…

Computation · Statistics 2022-06-28 Pierre Miasnikof , Alexander Y. Shestopaloff , Cristián Bravo , Yuri Lawryshyn

It is not hard to find many complete bipartite graphs which are not determined by their spectra. We show that the graph obtained by deleting an edge from a complete bipartite graph is determined by its spectrum. We provide some graphs, each…

Combinatorics · Mathematics 2016-01-27 Chia-an Liu , Chih-wen Weng

Two signed graphs are called switching isomorphic to each other if one is isomorphic to a switching of the other. The wheel $W_n$ is the join of the cycle $C_n$ and a vertex. For $0 \leq p \leq n$, $\psi_{p}(n)$ is defined to be the number…

Combinatorics · Mathematics 2021-09-17 Deepak Sehrawat , Bikash Bhattacharjya

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

In this paper, we describe {\sc quantitative graph theory} and argue it is a new graph-theoretical branch in network science, however, with significant different features compared to classical graph theory. The main goal of quantitative…

Social and Information Networks · Computer Science 2017-10-17 Matthias Dehmer , Frank Emmert-Streib , Yongtang Shi

We study countable graphs that -- up to isomorphism and with probability one -- arise from a random process, in a similar fashion as the Rado graph. Unlike in the classical case, we do not require that probabilities assigned to pairs of…

Combinatorics · Mathematics 2026-01-23 Ziemowit Kostana , Jarosław Swaczyna , Agnieszka Widz

A cograph is a simple graph that contains no induced path on four vertices. In this paper, we consider $\mathcal{C}$-graphs, which are a specific class of cographs, defined as $$\overline{\overline{\overline{K_{\alpha_{1}}}\cup…

Combinatorics · Mathematics 2025-09-23 Anjitha Ashokan , Chithra A

In this paper, we introduce a generalization of graphlets to heterogeneous networks called typed graphlets. Informally, typed graphlets are small typed induced subgraphs. Typed graphlets generalize graphlets to rich heterogeneous networks…

Social and Information Networks · Computer Science 2020-10-28 Ryan A. Rossi , Nesreen K. Ahmed , Aldo Carranza , David Arbour , Anup Rao , Sungchul Kim , Eunyee Koh

Random graphs with a given degree sequence are often constructed using the configuration model, which yields a random multigraph. We may adjust this multigraph by a sequence of switchings, eventually yielding a simple graph. We show that,…

Probability · Mathematics 2019-02-01 Svante Janson