On some properties of linear spaces and linear operators in the case of quaternionic scalars

In recent years the study of quaternionic linear spaces has been widely developed
by mathematicians and has been widely used by physicists. At the same
time it turns out that some basic and fundamental properties of those spaces
are not treated properly and this requires to develop the corresponding theory.
In this talk we will analyze certain peculiarities of the situation via the notion
of quaternionic extension of real and complex linear spaces as well as using the
notion of internal quaternionization. We will see, for example, how the norms of
some operators behave when they are “quaternionically extended”.