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  • Skew-adjacency matrices of ...
    Boussaïri, Abderrahim; Ezzahir, Sara; Lakhlifi, Soufiane; Mahzoum, Soukaïna

    Discrete mathematics, October 2023, 2023-10-00, Volume: 346, Issue: 10
    Journal Article

    Let T be a tournament with n vertices v1,…,vn. The skew-adjacency matrix of T is the n×n zero-diagonal matrix S=sij in which sij=−sji=1 if vi dominates vj. It is well-known that the determinant of S is zero or the square of an odd integer. Moreover, the principal minors of S are at most 1 if and only if T is a local order. In this paper, we characterize the class of tournaments for which the principal minors of the skew-adjacency matrix do not exceed 9.