Positive, Path-Product and Inverse M-matrices
 
 
Description:  An n-by-n, entry-wise nonnegative matrix is called an inverse M-matrix (IM) if it is invertible and its inverse has nonpositive off-diagonal entries. An irreducible IM amtrix is necessarily entry-wise positive. Both M-matrices and IM matrices arise in a wide array of applications, including to other parts of mathematics. It is known that an IM matrix is a (strict) path-product matrix (to be defined in talk), but not conversely. In general, recognition of IM matrices is delicate. We discuss a number of recent results relating path-product matrices and IM matrices, with emphasis on Hadamard powers of IM matrices.
Area(s):
Date:  2006-04-27
Start Time:   14:45
Speaker:  Charles R. Johnson (College of William and Mary, Williamsburg,USA)
Place:  5.5
Research Groups: -Algebra and Combinatorics
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