Czechoslovak Mathematical Journal

, Volume 56, Issue 3, pp 969–979 | Cite as

± sign pattern matrices that allow orthogonality

  • Yanling Shao
  • Liang Sun
  • Yubin Gao


A sign pattern A is a ± sign pattern if A has no zero entries. A allows orthogonality if there exists a real orthogonal matrix B whose sign pattern equals A. Some sufficient conditions are given for a sign pattern matrix to allow orthogonality, and a complete characterization is given for ± sign patterns with n − 1 ⩽ N(A) ⩽ n + 1 to allow orthogonality.


sign pattern orthogonality orthogonal matrix 


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Copyright information

© Mathematical Institute, Academy of Sciences of Czech Republic 2006

Authors and Affiliations

  • Yanling Shao
    • 1
  • Liang Sun
    • 2
  • Yubin Gao
    • 1
  1. 1.Department of MathematicsNorth University of ChinaTaiyuan, ShanxiP. R. China
  2. 2.Department of Applied MathematicsBeijing Institute of TechnologyBeijingP. R. China

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