“School of Mathematics”
Back to Papers HomeBack to Papers of School of Mathematics
Paper IPM / M / 7264  


Abstract:  
A complex matrix A is raynonsingular if det(X°A) ≠ 0 for every matrix X with positive entries. It is known taht
the order of a full raynonsingular matrix is at most 5 and
examples of full n×n raynonsingular matrices for
n=2,3,4 exist. In this note, we describe a property of a special
full 5×5 raynonsingular matrix, if such matrix exists,
using the concept of an isolated set of transversals and we obtain
a necessary condition for a complex matrix A to be
raynonsingular. Moreover we give an example of a full 5×5
raypattern matrix that satisfies all three of the properties
given by Lee et al.
Download TeX format 

back to top 