B. Chergui

activity

20162021

collaborators

Showing math.COShow all

5 papers · 1 filter

math.CO2021

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

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…

math.CO2016

A transformation that preserves principal minors of skew-symmetric matrices

Abderrahim Boussaïri, Brahim Chergui

Our motivation comes from the work of Engel and Schneider (1980). Their main theorem implies that two symmetric matrices have equal corresponding principal minors of all orders if…