We study the numerical range of bounded linear operators on quaternionic Hilbert spaces
and its relation with the S-spectrum. The class of complex operators on quaternionic Hilbert …

We study the essential numerical range of complex operators on a quaternionic Hilbert
space and its relation with the essential S-spectrum. We give a new characterization of the …

The article provides a concise overview of key concepts related to right quaternionic linear
operators, quaternionic Hilbert spaces, and quaternionic Krein spaces. It then delves into the …

In this paper, we establish and study some properties of the spatial numerical range of right
linear bounded operators on a right quaternionic Banach space. To be more specific, we …

The numerical range in the quaternionic setting is, in general, a non-convex subset of the
quaternions. The essential numerical range is a refinement of the numerical range that only …

Quaternionic Numerical Range Page 1 Quaternionic Numerical Range Helena Soares
Abstract Let T be a bounded linear operator on the complex Hilbert space H with inner product …

Abstract A flexible system A\B is a system of linear equations in which each coefficient and
each element of the right-hand side have an individual imprecision in terms of a scalar …

In 1951 Kippenhahn introduced the study of the numerical range for quaternionic operators
over finite-dimensional Hilbert spaces. A striking difference between the quaternionic and …