Normal matrices are an important class of matrices; many authors discuss the normality of matrices. In terms of projection matrices, the inverse of matrices, one-sided $ X $-equality, and $ X $-idempotency of matrices, many new characterizations of normal matrices are obtained in this paper. It may be the first time that the projection, one-sided $ X $-equality, and one-sided $ X $-idempotency are used to characterize the normality of matrices.
Citation: Zhirong Guo, Qianglian Huang. Some new characterizations of the normality for group invertible matrices[J]. AIMS Mathematics, 2025, 10(5): 12135-12148. doi: 10.3934/math.2025550
Normal matrices are an important class of matrices; many authors discuss the normality of matrices. In terms of projection matrices, the inverse of matrices, one-sided $ X $-equality, and $ X $-idempotency of matrices, many new characterizations of normal matrices are obtained in this paper. It may be the first time that the projection, one-sided $ X $-equality, and one-sided $ X $-idempotency are used to characterize the normality of matrices.
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