New sufficient conditions for subdirect sums of Nekrasov matrices

Abstract

Some new sufficient conditions ensuring that the $k$-subdirect sum of strictly diagonally dominant matrices and Nekrasov matrices is in the class of Nekrasov matrices are given. These sufficient conditions are different from those in [Electron. J. Linear Algebra, 38:339-346, 2022] and [Linear Multilinear Algebra, 64:208-218, 2016; 72:1044-1055, 2023]. In addition, some examples are given to illustrate the conditions presented.