B. Chergui

activity

20142024

most cited3-uniform hypergraphs: modular decomposition and realization by tournaments

2 citations · 3 across the 7 of their papers we have counts for

collaborators

9 papers

math.CO2024

Quasi-orthogonal extension of symmetric matrices

Abderrahim Boussaïri, Brahim Chergui, Zaineb Sarir +1

An $n \times n$ real matrix $Q$ is quasi-orthogonal if $Q^{⊤} Q = q I_{n}$ for some positive real number $q$ . If $M$ is a principal sub-matrix of a quasi-orthogonal matrix $Q$ , we sa…

math.CO2024

Quasi-orthogonal extension of skew-symmetric matrices

Abderrahim Boussaïri, Brahim Chergui, Zaineb Sarir +1

A real matrix $Q$ is quasi-orthogonal if $Q^{⊤} Q = q I$ , for some positive real number $q$ . We prove that any $n \times n$ skew-symmetric matrix $S$ is a principal sub-matrix of a s…

math.CO2021★ 1 cited

Generalized tournament matrices with the same principal minors

Abderrahim Boussaïri, Abdelhak Chaïchaâ, Brahim Chergui +1

A generalized tournament matrix $M$ is a nonnegative matrix that satisfies $M + M^{t} = J - I$ , where $J$ is the all ones matrix and $I$ is the identity matrix. In this paper, a characte…

math.CO2020

Critical 3-hypergraphs (detailed version)

Abderrahim Boussairi, Brahim Chergui, Pierre Ille +1

Given a 3-hypergraph $H$ , a subset $M$ of $V (H)$ is a module of $H$ if for each $e \in E (H)$ such that $e \cap M \neq = \emptyset$ and $e ∖ M \neq = \emptyset$ , there exists $m \in M$ …

math.CO2019

On the spectral reconstruction problem for digraphs

Edward Bankoussou-mabiala, Abderrahim Boussaïri, Abdelhak Chaïchaâ +2

The idiosyncratic polynomial of a graph $G$ with adjacency matrix $A$ is the characteristic polynomial of the matrix $A + y (J - A - I)$ , where $I$ is the identity matrix and $J$ is th…

math.CO2018★ 2 cited

3-uniform hypergraphs: modular decomposition and realization by tournaments

Abderrahim Boussaïri, Brahim Chergui, Pierre Ille +1

Let $H$ be a 3-uniform hypergraph. A tournament $T$ defined on $V (T) = V (H)$ is a realization of $H$ if the edges of $H$ are exactly the 3-element subsets of $V (T)$ that induce 3-cyc…