Asghar Bahmani

activity

20152019

most citedGraph reduction techniques and the multiplicity of the Laplacian eigenvalues

4 citations · 4 across the 5 of their papers we have counts for

collaborators

Showing math.COShow all

5 papers · 1 filter

math.CO2019

Structure of Trees with Respect to Nodal Vertex Sets

Asghar Bahmani, Dariush Kiani

Let $T$ be a tree with a given adjacency eigenvalue $λ$ . In this paper, by using the $λ$ -minimal trees, we determine the structure of trees with a given multiplicity of the eigenva…

math.CO2018

A counterexample to a conjecture of Wang and Hou on signed graphs

Asghar Bahmani

We give a counterexample to a conjecture of Wang and Hou related with the sum of the $k$ largest Laplacian eigenvalues of signed graphs.

math.CO2018

Convex functions on graphs: Sum of the eigenvalues

Asghar Bahmani

Let $G$ be a simple graph with the Laplacian matrix $L (G)$ and let $e (G)$ be the number of edges of $G$ . A conjecture by Brouwer and a conjecture by Grone and Merris state that the…

math.CO2016

An Explicit Formula for the Eigenvectors of Acyclic Matrices and Weighted Trees

Asghar Bahmani, Dariush Kiani

Let $A$ be an acyclic symmetric matrix of order $n$ . There is a weighted forest $F$ whose adjacency matrix is $A$ . In this paper, using some results on matching polynomials, we pro…

math.CO2015★ 4 cited

Graph reduction techniques and the multiplicity of the Laplacian eigenvalues

Asghar Bahmani, Dariush Kiani

Let $M = [m_{ij}]$ be an $n \times m$ real matrix, $ρ$ be a nonzero real number, and $A$ be a symmetric real matrix. We denote by $D (M)$ the $n \times n$ diagonal matrix $diag(\sum_{j=…