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Related papers: Spectra of Complex Unit Hypergraphs

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This paper develops analityc methods for investigating uniform hypergraphs. Its starting point is the spectral theory of 2-graphs, in particular, the largest and the smallest eigenvalues of 2-graphs. On the one hand, this simple setup is…

Combinatorics · Mathematics 2013-08-14 Vladimir Nikiforov

We show that there exists an adjacency labelling scheme for planar graphs where each vertex of an $n$-vertex planar graph $G$ is assigned a $(1+o(1))\log_2 n$-bit label and the labels of two vertices $u$ and $v$ are sufficient to determine…

Data Structures and Algorithms · Computer Science 2021-12-03 Vida Dujmović , Louis Esperet , Gwenaël Joret , Cyril Gavoille , Piotr Micek , Pat Morin

We say that a $k$-uniform hypergraph $C$ is a Hamilton cycle of type $\ell$, for some $1\le \ell \le k$, if there exists a cyclic ordering of the vertices of $C$ such that every edge consists of $k$ consecutive vertices and for every pair…

Combinatorics · Mathematics 2011-02-09 Deepak Bal , Alan Frieze

A (simple) hypergraph is a family H of pairwise incomparable sets of a finite set. We say that a hypergraph H is a domination hypergraph if there is at least a graph G such that the collection of minimal dominating sets of G is equal to H.…

Combinatorics · Mathematics 2016-05-06 Jaume Martí-Farré , Mercè Mora , José Luis Ruiz

A hypergraph is linear if each pair of distinct vertices appears in at most one common edge. We say $\varGamma=(V,E)$ is an associated graph of a linear hypergraph $\mathcal{H}=(V, X)$ if for any $x\in X$, the induced subgraph…

Combinatorics · Mathematics 2025-03-25 Kai Yuan , Qi Wang , Rongquan Feng , Yan Wang

We prove an asymptotic formula for the number of $k$-uniform hypergraphs with a given degree sequence, for a wide range of parameters. In particular, we find a formula that is asymptotically equal to the number of $d$-regular $k$-uniform…

Combinatorics · Mathematics 2022-02-01 Nina Kamčev , Anita Liebenau , Nick Wormald

Let A(G) be the adjacency tensor (hypermatrix) of uniform hypergraph G. The maximum modulus of the eigenvalues of A(G) is called the spectral radius of G. In this paper, the conjecture of Fan et al. in [5] related to compare the spectral…

Combinatorics · Mathematics 2016-05-09 Liying Kang , Lele Liu , Liqun Qi , Xiying Yuan

In this paper, we introduce the class of cored hypergraphs and power hypergraphs, and investigate the properties of their Laplacian H-eigenvalues. From an ordinary graph, one may generate a $k$-uniform hypergraph, called the $k$th power…

Spectral Theory · Mathematics 2013-04-26 Shenglong Hu , Liqun Qi , Jia-Yu Shao

A Kirchhoff graph is a vector graph with orthogonal cycles and vertex cuts. An algorithm has been developed that constructs all the Kirchhoff graphs up to a fixed edge multiplicity. This algorithm is used to explore the structure of prime…

Combinatorics · Mathematics 2022-07-26 Jessica Wang , Joseph Fehribach

For $0\leq \alpha < 1$, the $\mathcal{A}_{\alpha}$-spectral radius of a $k$-uniform hypergraph $G$ is defined to be the spectral radius of the tensor $\mathcal{A}_{\alpha}(G):=\alpha \mathcal{D}(G)+(1-\alpha) \mathcal{A}(G)$, where…

Combinatorics · Mathematics 2021-09-09 Peng-Li Zhang , Xiao-Dong Zhang

We find an asymptotic enumeration formula for the number of simple $r$-uniform hypergraphs with a given degree sequence, when the number of edges is sufficiently large. The formula is given in terms of the solution of a system of equations.…

Combinatorics · Mathematics 2022-05-18 Catherine Greenhill , Mikhail Isaev , Tamás Makai , Brendan D. McKay

We establish a lower bound for the energy of a complex unit gain graph in terms of the matching number of its underlying graph, and characterize all the complex unit gain graphs whose energy reaches this bound.

Combinatorics · Mathematics 2020-05-06 Yuxuan Li

A mixed hypergraph is a triple $H=(V,\mathcal{C},\mathcal{D})$, where $V$ is a set of vertices, $\mathcal{C}$ and $\mathcal{D}$ are sets of hyperedges. A vertex-coloring of $H$ is proper if $C$-edges are not totally multicolored and…

Combinatorics · Mathematics 2014-07-08 Maria Axenovich , Enrica Cherubini , Torsten Ueckerdt

We introduce a taxonomy of interaction types and show that graphs are focal hypergraphs: every graph is canonically a focal hypergraph via its closed neighbourhood structure, and every graph dynamical model is a special case of the general…

Physics and Society · Physics 2026-03-05 Elkaïoum M. Moutuou

In this note we elaborate on some notions of surface area for discrete graphs which are closely related to the inverse degree. These notions then naturally lead to associated connectivity measures of graphs and to the definition of a…

Combinatorics · Mathematics 2026-03-09 Patrizio Bifulco , Joachim Kerner

In this paper we obtain bounds for the extreme entries of the principal eigenvector of hypergraphs; these bounds are computed using the spectral radius and some classical parameters such as maximum and minimum degrees. We also study…

Spectral Theory · Mathematics 2019-11-20 Kauê Cardoso , Vilmar Trevisan

A complex unit gain graph ($\mathbb{T}$-gain graph), $\Phi = (G, \varphi)$ is a graph where the function $\varphi$ assigns a unit complex number to each orientation of an edge of $G$, and its inverse is assigned to the opposite orientation.…

Combinatorics · Mathematics 2021-05-11 M. Rajesh Kannan , Navish Kumar , Shivaramakrishna Pragada

We present progress on the problem of asymptotically describing the adjacency eigenvalues of random and complete uniform hypergraphs. There is a natural conjecture arising from analogy with random matrix theory that connects these spectra…

Combinatorics · Mathematics 2018-01-10 Joshua Cooper

For a given complex square matrix $A$ with constant row sum, we establish two new eigenvalue inclusion sets. Using these bounds, first we derive bounds for the second largest and smallest eigenvalues of adjacency matrices of $k$-regular…

Combinatorics · Mathematics 2020-08-27 Ranjit Mehatari , M. Rajesh Kannan

An r-cut of a k-uniform hypergraph H is a partition of the vertex set of H into r parts and the size of the cut is the number of edges which have a vertex in each part. A classical result of Edwards says that every m-edge graph has a 2-cut…

Combinatorics · Mathematics 2019-07-01 David Conlon , Jacob Fox , Matthew Kwan , Benny Sudakov