Invertible completions of partial operator matrices: The nonsymmetric case

Invertible and regular completions of operator matrices

completions on partial matrices ?

An n × n matrix is called an N0-matrix if all its principal minors are nonpositive. In this paper, we are interested in N0-matrix completion problems, that is, when a partial N0-matrix has an N0-matrix completion. In general, a combinatorially or non-combinatorially symmetric partial N0-matrix does not have an N0-matrix completion. Here, we prove that a combinatorially symmetric partial N0-matr...

Totally nonpositive completions on partial matrices ∗ †

An n × n real matrix is said to be totally nonpositive if every minor is nonpositive. In this paper, we are interested in totally nonpositive completion problems, that is, does a partial totally nonpositive matrix have a totally nonpositive matrix completion? This problem has, in general, a negative answer. Therefore, we analyze the question: for which labeled graphs G does every partial totall...

Sums of Alternating Matrices and Invertible Matrices

A square matrix is said to be alternating-clean if it is the sum of an alternating matrix and an invertible matrix. In this paper, we determine all alternating-clean matrices over any division ring K. If K is not commutative, all matrices are alternating-clean, with the exception of the 1× 1 zero matrix. If K is commutative, all matrices are alternating-clean, with the exception of odd-size alt...

pricing unemployment insurance : the case of iran

employees always concern about losing their job , or in other word , losing their income resources. for this purpose, every government requires strong system for covering these concerns. the unemployment insurance (ui) program’s can be used for achieving this goal. in this thesis, we price ui based on the insurance history of employee and the duration of being unemployed. we use the weibull dis...