Asghar Bahmani

collaborators

3 papers

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…