# EXTREMAL CASES OF SN-MATRICES

Kim, Si-Ju;Choi, Tae-Young

• Received : 2008.07.21
• Accepted : 2008.09.01
• Published : 2008.12.25
• 29 3

#### Abstract

We denote by $\mathcal{Q}$(A) the set of all real matrices with the same sign pattern as a real matrix A. A matrix A is an SN-matrix provided there exists a set S of sign pattern such that the set of sign patterns of vectors in the -space of $\tilde{A}$ is S, for each ${\tilde{A}}{\in}\mathcal{Q}(A)$. Some properties of SN-matrices arc investigated.

#### Keywords

zero patterns;conformal contractions;signed null-spaces

#### References

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