On a class of matrices which arise in the numerical solution of Euler equations.
Let A be an n×n irreducible nonnegative (elementwise) matrix. Borobia and Moro raised the following question: Suppose that every diagonal of A contains a positive entry. Is A similar to a positive matrix? We give an affirmative answer in the case n = 4.
The objective of this manuscript is to investigate the structure of linear maps on the space of real symmetric matrices that leave invariant the closed convex cones of copositive and completely positive matrices ( and ). A description of an invertible linear map on such that is obtained in terms of semipositive maps over the positive semidefinite cone and the cone of symmetric nonnegative matrices for , with specific calculations for . Preserver properties of the Lyapunov map , the...
The partial ordering induced by the Loewner partial ordering on the convex cone comprising all matrices which multiplied by a given positive definite matrix become nonnegative definite is considered. Its relation to orderings which are induced by the Loewner partial ordering of the squares of matrices is presented. Some extensions of the latter orderings and their comparison to star orderings are given.