Let E be a Banach lattice, T be a bounded operator on E. The Weyl essential spectrum σew(T ) of the operator T is a set σew(T ) = ∩ K∈K(E) σ(T + K), where K(E) is a set of all compact operators on E. In particular for a positive operator T next subsets of the spectrum

Let T be a positive operator on a Banach lattice E. Some properties of Weyl essential spectrum σew(T ), in particular, the equality σew(T ) = ⋂ 0≤K∈K(E) σ(T +K), where K(E) is the set of all compact operators on E, are established. If r(T ) does not belong to Fredholm essential spectrum σef(T ), then r(T ) 6∈ σ(T +a|T−1|) for every a 6= 0, where T−1 is a residue of the resolvent R(., T ) at r(T...

tagetes is a genus of 56 species of annual and perennial mostly herbaceous plants in the sunflower family (asteraceae or compositae).in this research our goal was recognizing the main components of the plant to extract useful ones. essential oils of the leaves, seeds and flowers of tagets minuta l., growing wild in iran, were extracted by hydrodistillation and analyzed by gc and gc-ms. identifi...

In this article, the relationships between $S$-spectra, $ S$-spectral radius, \epsilon$-$S$-essential pseudospectra, and pseudospectral radius of diagonal block operator matrices in direct sum Banach spaces their coordinate operators are studied. Then, results supported by applications.