Linear transformations of variance/covariance matrices

Matrices and Linear Transformations

Linear Transformations on Matrices *

Even in thi s generality , it is clear that .!l' (I , ~) is a multiplicative se migroup with an ide ntity. The invariant I can be a scalar valued fun ction, e.g. , I (X) = det (X) ; or for that matter it can describe a property, e.g., m can equal M" (C) and I (X) can mean that X is unitary , so that we are simply asking for the s tructure of all linear transformation s T that map the unitary gr...

2: Linear Transformations and Matrices

The general approach to the foundations of mathematics is to study certain spaces, and then to study functions between these spaces. In this course we follow this paradigm. Up until now, we have been studying properties of vector spaces. Vector spaces have a linear structure, and so it is natural to deal with functions between vector spaces that preserve this linear structure. That is, we will ...

On One-Sided Ideals of Rings of Linear Transformations

A brief introduction to quaternion matrices and linear algebra and on bounded groups of quaternion matrices

The division algebra of real quaternions, as the only noncommutative normed division real algebra up to isomorphism of normed algebras, is of great importance. In this note, first we present a brief introduction to quaternion matrices and quaternion linear algebra. This, among other things, will help us present the counterpart of a theorem of Herman Auerbach in the setting of quaternions. More ...