Abstract: In this paper, the definitions of the quaternion measure
and the quaternion vector measure are introduced. The relation
between the quaternion measure and the complex vector measure
as well as the relation between the quaternion linear functional and
the complex linear functional are discussed respectively. By using
these relations, the necessary and sufficient condition to determine
the quaternion vector measure is given.
Abstract: In this paper, the similarity invariant and the upper
semi-continuity of spherical spectrum, and the spherical spectrum
properties for infinite direct sums of quaternionic operators are
characterized, respectively. As an application of some results
established, a concrete example about the computation of the
spherical spectrum of a compact quaternionic operator with form of
infinite direct sums of quaternionic matrices is also given.
Abstract: In this paper, we discuss some properties of left
spectrum and give the representation of linear preserver map the left
spectrum of diagonal quaternionic matrices.