Subdirect Sums of S-strictly Diagonally Dominant Matrices *
نویسندگان
چکیده
Conditions are given which guarantee that the k-subdirect sum of S-strictly diagonally dominant matrices (S-SDD) is also S-SDD. The same situation is analyzed for SDD matrices. The converse is also studied: given an SDD matrix C with the structure of a k-subdirect sum and positive diagonal entries, it is shown that there are two SDD matrices whose subdirect sum is C. AMS subject classifications. 15A48, 15A18, 65F15.
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