activity
20152026
most citedResolvent Energy of Unicyclic, Bicyclic and Tricyclic Graphs

8 citations · 10 across the 11 of their papers we have counts for

collaborators

14 papers

math.CO2026

On the minimum number of eigenvalues of matrices associated with cographs

Luiz Emilio Allem, Martin Fürer, Carlos Hoppen +2

A symmetric matrix is said to be associated with an -vertex graph with vertex set if, for every $i \neq j…

cs.SI2025

Multi-Community Spectral Clustering for Geometric Graphs

Luiz Emilio Allem, Konstantin Avrachenkov, Carlos Hoppen +2

In this paper, we consider the soft geometric block model (SGBM) with a fixed number of homogeneous communities in the dense regime, and we introduce a spectral clusteri…

math.CO2025

The minimum number of distinct eigenvalues of a threshold graph is at most

Luiz Emilio Allem, Carlos Hoppen, João Lazzarin +2

In this note we show that the minimum number of distinct eigenvalues of a threshold graph is at most . Moreover, given any threshold graph and any nonzero real number , w…

math.CO2025

On the minimum number of eigenvalues of trees of diameter seven

Luiz Emilio Allem, Carlos Hoppen, Lucas Siviero Sibemberg

The underlying graph of a symmetric matrix is the graph with vertex set such that a pair with $i\neq j…

math.CO2023

Diminimal families of arbitrary diameter

Luiz Emilio Allem, Rodrigo Orsini Braga, Carlos Hoppen +3

Given a tree , let be the minimum number of distinct eigenvalues in a symmetric matrix whose underlying graph is . It is well known that , where $d(T)…

math.CO2021

On I-eigenvalue free threshold graphs

Luiz Emilio Allem, Elismar R. Oliveira, Fernando Tura

A graph is said to be I-eigenvalue free if it has no eigenvalues in the interval I with respect to the adjacency matrix A. In this paper we present two algorithms for generating I-…