English
Related papers

Related papers: Maximal digraphs whose Hermitian spectral radius i…

200 papers

For a given set of dilations $E\subset [1,2]$, Lebesgue space mapping properties of the spherical maximal operator with dilations restricted to $E$ are studied when acting on radial functions. In higher dimensions, the type set only depends…

Classical Analysis and ODEs · Mathematics 2026-03-02 David Beltran , Joris Roos , Andreas Seeger

This paper investigates the influence of two graft transformations on the distance spectral radius of connected uniform hypergraphs. Specifically, we study $k$-uniform hypertrees with given size, maximum degree and number of vertices of…

Combinatorics · Mathematics 2024-03-15 Xiaoqi Liu , Haiying Shan

The odd wheel $W_{2k+1}$ is the graph formed by joining a vertex to a cycle of length $2k$. In this paper, we investigate the largest value of the spectral radius of the adjacency matrix of an $n$-vertex graph that does not contain…

Combinatorics · Mathematics 2021-04-19 Sebastian Cioabă , Dheer Noal Desai , Michael Tait

Spectral graph bisections are a popular heuristic aimed at approximating the solution of the NP-complete graph bisection problem. This technique, however, does not always provide a robust tool for graph partitioning. Using a special class…

Numerical Analysis · Mathematics 2015-12-22 John C. Urschel , Ludmil T. Zikatanov

A connected graph is called a bi-block graph if each of its blocks is a complete bipartite graph. Let $\mathcal{B}(\mathbf{k}, \alpha)$ be the class of bi-block graph on $\mathbf{k}$ vertices with given independence number $\alpha$. It is…

Combinatorics · Mathematics 2020-12-18 Joyentanuj Das , Sumit Mohanty

Let $G$ be a digraph with adjacency matrix $A(G)$. Let $D(G)$ be the diagonal matrix with outdegrees of vertices of $G$. Nikiforov \cite{Niki} proposed to study the convex combinations of the adjacency matrix and diagonal matrix of the…

Combinatorics · Mathematics 2021-05-25 Weige Xi , Ligong Wang

For a connected graph, the distance spectral radius is the largest eigenvalue of its distance matrix. In this paper, of all trees with both given order and fixed diameter, the trees with the minimal distance spectral radius are completely…

Combinatorics · Mathematics 2013-10-24 Guanglong Yu , Shuguang Guo , Mingqing Zhai

We give a density condition for when, subject to a necessary parity condition, an eulerian graph or digraph may be cellularly embedded in an orientable surface so that it has exactly two faces, each bounded by an euler circuit, one of which…

Combinatorics · Mathematics 2024-09-24 M. N. Ellingham , Joanna A. Ellis-Monaghan

We give two lower bounds on the largest order of an arc-transitive graph of diameter two and a given degree.

Combinatorics · Mathematics 2013-12-24 Sanming Zhou

In this paper, we give some bounds for principal eigenvector and spectral radius of connected uniform hypergraphs in terms of vertex degrees, the diameter, and the number of vertices and edges.

Combinatorics · Mathematics 2016-05-30 Haifeng Li , Jiang Zhou , Changjiang Bu

In this paper we determine the unique graph with minimum distance spectral radius among all connected graphs of fixed order and given edge connectivity.

Combinatorics · Mathematics 2014-09-19 Xiao-Xin Li , Yi-Zheng Fan , Yi Wang

The diameter of a graph measures the maximal distance between any pair of vertices. The diameters of many small-world networks, as well as a variety of other random graph models, grow logarithmically in the number of nodes. In contrast, the…

Combinatorics · Mathematics 2011-04-05 Jens Marklof , Andreas Strömbergsson

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

If $G$ is a claw-free hamiltonian graph of order $n$ and maximum degree $\Delta$ with $\Delta\geq 24$, then $G$ has cycles of at least $\min\left\{ n,\left\lceil\frac{3}{2}\Delta\right\rceil\right\}-2$ many different lengths.

Combinatorics · Mathematics 2013-12-05 Jonas Eckert , Felix Joos , Dieter Rautenbach

In this paper, the extremal graph with the maximum RRD-value among all the graphs of order n with given cut vertices or edges is characterized. In addition, an upper bounds on the reciprocal degree distance in terms of the number of cut…

Combinatorics · Mathematics 2015-03-12 Xiao-Xin Li

This paper generalizes and unifies the existing spectral bounds on the $k$-independence number of a graph, which is the maximum size of a set of vertices at pairwise distance greater than $k$. The previous bounds known in the literature…

Combinatorics · Mathematics 2018-08-28 A. Abiad , G. Coutinho , M. A. Fiol

Let $G$ be a finite, connected graph and $v$ a vertex of $G$. The average distance and the eccentricity of $v$ in $G$ are defined as the arithmetic mean and the maximum, respectively, of the distances from $v$ to all other vertices of $G$.…

Combinatorics · Mathematics 2025-08-15 Peter Dankelmann , Sonwabile Mafunda , Sufiyan Mallu

We describe the structure of those graphs that have largest spectral radius in the class of all connected graphs with a given degree sequence. We show that in such a graph the degree sequence is non-increasing with respect to an ordering of…

Combinatorics · Mathematics 2008-10-07 Tuerker Biyikoglu , Josef Leydold

We show that every 2-degenerate graph with maximum degree $\Delta$ has a strong edge-coloring with at most $8\Delta-4$ colors.

Combinatorics · Mathematics 2024-03-28 Rong Luo , Gexin Yu

A positive definite Hermitian lattice is said to be 2-universal if it represents all positive definite binary Hermitian lattices. We find all 2-universal ternary and quaternary Hermitian lattices over imaginary quadratic number fields.

Number Theory · Mathematics 2008-10-09 Myung-Hwan Kim , Poo-Sung Park