5 Results Found

The spectral property $\left(\omega \pi \right)$ generalizes the a-Weyl theorem and characterizes the relationships between the spectrum and the upper semi-Fredholm spectrum. This paper proves that any nonzero scalar multiple of an operator verifying the property...

Given a complex Banach space $\mathcal{X}$, we investigate the stable character of the property $\left(V_E\right)$ for a bounded linear operator $\mathcal{T}:\mathcal{X}\to \mathcal{X}$, under commuting perturbations that are Riesz, compact, algebraic and hereditarily polaroid. We also analyze sufficient condi...

Let H be an infinite-dimensional separable complex Hilbert space and $B\left(H\right)$ the algebra of all bounded linear operators on H. In this paper, we characterized the linear maps $\varphi :B\left(H\right)\to B\left(H\right)$, which are surjective up to compact operators preserving...

The primary aim of this manuscript is to establish unique fixed point results for a class of $\Psi$-contraction operators in complete G-metric spaces. By combining and extending various fixed point theorems in the context of $\Psi$-contraction operator...

The calculation of low frequency expansions for acoustic wave scattering has been under thorough investigation for many decades due to their utility in technological applications. In the present work, we revisit the acoustic Low Frequency Scattering...