In this paper, some properties of compact operators on quaternionic Hilbert spaces are studied. It is shown that the positiveness of a compact normal operator on a quaternionic Hilbert space is equivalent to positiveness of its eigenvalues. Some...

-Smulian theorem. Also, we apply this observation on study compact operators on right quaternionic Hilbert spaces....

The concept of unbounded Fredholm operators on Hilbert C*-modules over an arbitrary C*-algebra is discussed and the Atkinson theorem is generalized for bounded and unbounded Fredholm operators on Hilbert C*-modules over compact operators....

We define a spectrally compact operator between two spectrally normed spaces. We show that every spectrally compact operator is compact but the converse is not true in general. Some basic aspects of these operayors are also proved....

assertions about the norm--parallelism of compact operators.
Some applications and generalizations are discussed for certain operators....

‎In this paper‎, ‎we present some characterizations of linear mappings‎, ‎which preserve vectors at a specific angle‎. ‎We introduce the concept of $-varepsilon‎, ‎c-$-angle preserving mappings for $|c|<1$ and $0leq ...

We intoduce spectrally compact operators. We show that these operators are compact and spectrally bounded....

We show that the unit ball of a full Hilbert C∗ -module is sequentially compact in

a certain weak topology if and only if the underlying C∗ -algebra is finite dimensional. This

provides an answer to the ...

results for densely defined closed operators on Hilbert

$C^*$-modules over $C^*$-algebras of compact operators....

We investigate shift preserving operators on locally compact abelian

groups. We show that there is a one-to-one correspondence between shift preserving

operators and range operators on L2(G) where G is a ...