M. Ebrahimi

activity

20122023

most citedPerturbed N=(2,2) supersymmetric sigma models on Lie groups

1 citations · 2 across the 12 of their papers we have counts for

collaborators

14 papers

math.CO2023

Integral Cayley graphs of symmetric groups on transpositions

Alireza Abdollahi, Majid Arezoomand, Mahdi Ebrahimi

We study subsets $T$ consisting of some transpositions $(i, j)$ of the symmetric group $S_{n}$ on ${1, \dots, n}$ such that the Cayley graph $Γ_{T} := C a y (S_{n}, T)$ is an integral graph, i.…

math.CO2023

Littlewood-Richardson coefficients and the eigenvalues of integral line graphs

Mahdi Ebrahimi

We first describe a system of inequalities (Horn's inequalities) that characterize eigenvalues of sums of Hermitian matrices. When we apply this system for integral Hermitian matri…

math.CO2023

A hook formula for eigenvalues of k-point fixing graph

Mahdi Ebrahimi

Let $S_{n}$ denote the symmetric group on $n$ letters. The $k$ -point fixing graph $F (n, k)$ is defined to be the graph with vertex set $S_{n}$ and two vertices $g, h$ of $\math…

math.GR2021

Regular character-graphs whose eigenvalues are greater than or equal to -2

Mahdi Ebrahimi, Maryam Khatami, Zohreh Mirzaei

Let $G$ be a finite group and $Irr (G)$ be the set of all complex irreducible characters of $G$ . The character-graph $Δ (G)$ associated to $G$ , is a graph whose vertex set i…

math.GR2020

Groups in which the co-degrees of the irreducible characters are distinct

Mahdi Ebrahimi

Let $G$ be a finite group and let $Irr (G)$ be the set of all irreducible complex characters of $G$ . For a character $χ \in Irr (G)$ , the number $\rm{cod}(χ):=|G:\rm{ker}χ|/…

math.GR2020

$K_{4}$ -free character graphs with diameter three

Mahdi Ebrahimi

Let $G$ be a finite group and let $Irr (G)$ be the set of all irreducible complex characters of $G$ . Let $cd (G)$ be the set of all character degrees of $G$ and denote by $…

Integral Cayley graphs of symmetric groups on transpositions

Littlewood-Richardson coefficients and the eigenvalues of integral line graphs

A hook formula for eigenvalues of k-point fixing graph

Regular character-graphs whose eigenvalues are greater than or equal to -2

Groups in which the co-degrees of the irreducible characters are distinct

K4​-free character graphs with diameter three

$K_{4}$ -free character graphs with diameter three