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In this paper, we provide the irregularity properties of trees with strong support vertex by analyzing two prominent topological indices: the Albertson index and the Sigma index. We further establish extremal bounds for both indices across…

Combinatorics · Mathematics 2025-05-13 Jasem Hamoud , Duaa Abdullah

We propose a novel technique, termed compact shape trees, for computing correspondences of single-boundary 2-D shapes in O(n2) time. Together with zero or more features defined at each of n sample points on the shape's boundary, the compact…

Computer Vision and Pattern Recognition · Computer Science 2015-06-10 Abdulrahman Oladipupo Ibraheem

Symmetric Jacobi matrices on one sided homogeneous trees are studied. Essential selfadjointness of these matrices turns out to depend on the structure of the tree. If a tree has one end and infinitely many origin points the matrix is always…

Functional Analysis · Mathematics 2009-07-09 Agnieszka M. Kazun , Ryszard Szwarc

Complex numbers define the relationship between entities in many situations. A canonical example would be the off-diagonal terms in a Hamiltonian matrix in quantum physics. Recent years have seen an increasing interest to extend the tools…

Social and Information Networks · Computer Science 2023-07-06 Yu Tian , Renaud Lambiotte

It is a classical result that any finite tree with positively weighted edges, and without vertices of degree 2, is uniquely determined by the weighted path distance between each pair of leaves. Moreover, it is possible for a (small) strict…

Combinatorics · Mathematics 2012-09-12 Katharina T. Huber , Mike Steel

A spanning tree of a graph is a connected subgraph on all vertices with the minimum number of edges. The number of spanning trees in a graph $G$ is given by Matrix Tree Theorem in terms of principal minors of Laplacian matrix of $G$. We…

Combinatorics · Mathematics 2018-05-15 Keivan Hassani Monfared , Sudipta Mallik

This article deals with the spectra of Laplacians of weighted graphs. In this context, two objects are of fundamental importance for the dynamics of complex networks: the second eigenvalue of such a spectrum (called algebraic connectivity)…

Mathematical Physics · Physics 2017-04-07 Camille Poignard , Tiago Pereira , Jan Philipp Pade

For a graph \(G\) with no isolated vertices, its Laplacian ratio is defined as \[ \pi(G)=\frac{\operatorname{per}(L(G))}{\prod_{v\in V(G)} d(v)}, \] where \(L(G)\) is the Laplacian matrix of \(G\), \(d(v)\) is the degree of \(v\), and…

Combinatorics · Mathematics 2026-05-15 Priyanshu Pant

The investigation of social networks is often hindered by their size as such networks often consist of at least thousands of vertices and edges. Hence, it is of major interest to derive compact structures that represent important…

Social and Information Networks · Computer Science 2023-09-28 Maximilian Stubbemann , Gerd Stumme

We investigate spatial random graphs defined on the points of a Poisson process in $d$-dimensional space, which combine scale-free degree distributions and long-range effects. Every Poisson point is assigned an independent weight. Given the…

Probability · Mathematics 2024-04-23 Peter Gracar , Lukas Lüchtrath , Peter Mörters

We establish an inequality which involves a non-negative function defined on the vertices of a finite $m$-ary regular rooted tree. The inequality may be thought of as relating an interaction energy defined on the free vertices of the tree…

Classical Analysis and ODEs · Mathematics 2014-10-24 Kenneth J Falconer

We present a tree-based construction of LDPC codes that have minimum pseudocodeword weight equal to or almost equal to the minimum distance, and perform well with iterative decoding. The construction involves enumerating a $d$-regular tree…

Information Theory · Computer Science 2007-07-13 Christine Kelley , Deepak Sridhara , Joachim Rosenthal

We study the simple random walk on trees and give estimates on the mixing and relaxation time. Relying on a recent characterization by Basu, Hermon and Peres, we give geometric criteria, which are easy to verify and allow to determine…

Probability · Mathematics 2021-04-13 Nina Gantert , Evita Nestoridi , Dominik Schmid

We consider linear codes over a finite field of odd characteristic, derived from determinantal varieties, obtained from symmetric matrices of bounded ranks. A formula for the weight of a code word is derived. Using this formula, we have…

Information Theory · Computer Science 2023-12-25 Peter Beelen , Trygve Johnsen , Prasant Singh

Suppose we label the vertices of a tree by positive integers. The weight of an edge is defined by a monotonically increasing function of the absolute value of the difference of the labels of its endpoints. We define the total cost of the…

Data Structures and Algorithms · Computer Science 2013-05-27 Alexander Bolshoy , Valery Kirzhner

We introduce a new class of tree-based models, P-Trees, for analyzing (unbalanced) panel of individual asset returns, generalizing high-dimensional sorting with economic guidance and interpretability. Under the mean-variance efficient…

Machine Learning · Computer Science 2025-02-05 Lin William Cong , Guanhao Feng , Jingyu He , Xin He

We study random trees which are invariant in law under the operation of contracting each edge independently with probability $p\in(0,1)$. We show that all such trees can be constructed through Poissonian sampling from a certain class of…

Probability · Mathematics 2018-06-20 Olivier Hénard , Pascal Maillard

Assume that we embed the path $P_n$ as a subgraph of a $2$-dimensional grid, namely, $P_k \times P_l$. Given such an embedding, we consider the ordered set of subpaths $L_1, L_2, \ldots , L_m$ which are maximal straight segments in the…

Combinatorics · Mathematics 2018-03-23 Susana-Clara López , Francesc-Antoni Muntaner-Batle

Given a rooted tree $T$ with leaves $v_1,v_2,\ldots,v_n$, we define the ancestral matrix $C(T)$ of $T$ to be the $n \times n$ matrix for which the entry in the $i$-th row, $j$-th column is the level (distance from the root) of the first…

Combinatorics · Mathematics 2018-09-11 Eric O. D. Andriantiana , Kenneth Dadedzi , Stephan Wagner

The signless Laplacian Q and signless edge-Laplacian S of a given graph may or may not be invertible. The Moore-Penrose inverses of Q and S are studied. In particular, using the incidence matrix, we find combinatorial formulas of the Moore-…

Combinatorics · Mathematics 2020-05-11 Ryan Hessert , Sudipta Mallik