On the problem of invariance under holomorphic functions for a set of continuity points of the spectrum function
On the semi-Browder spectrum
An operator in a Banach space is called upper (lower) semi-Browder if it is upper (lower) semi-Fredholm and has a finite ascent (descent). We extend this notion to n-tuples of commuting operators and show that this notion defines a joint spectrum. Further we study relations between semi-Browder and (essentially) semiregular operators.
On The Set Of Operators Having A Given Simply Connected Spectral Set.
On the spectcral theory of elliptic differential operators. I.
On the Spectra of Certain Semi-Groups.
On the spectra of elements in certain algebras of vector valued functions and sequences.
On the spectra of some non-normal operators.
On the Spectral Kernel of Symmetric Extensions.
On the spectral multiplicity of a direct sum of operators
We calculate the spectral multiplicity of the direct sum T⊕ A of a weighted shift operator T on a Banach space Y which is continuously embedded in and a suitable bounded linear operator A on a Banach space X.
On the spectral properties of tensor products of linear operators in Banach spaces
On the spectral properties of translation operators in one-dimensional tubes
We study the spectral properties of some group of unitary operators in the Hilbert space of square Lebesgue integrable holomorphic functions on a one-dimensional tube (see formula (1)). Applying the Genchev transform ([2], [5]) we prove that this group has continuous simple spectrum (Theorem 4) and that the projection-valued measure for this group has a very explicit form (Theorem 5).
On the spectral radius of positive operators.
On the spectral radius of positive operators (Corrigendum).
On the spectrum and eigenfunctions of the operator
On the spectrum of a morphism of quotient Hilbert spaces.
On the spectrum of a one-parameter strongly continous representation.
On the spectrum of multipliers in Bessel potential spaces
On the spectrum of singularly perturbed operators
On the spectrum of stochastic perturbations of the shift and Julia sets
We extend the Killeen-Taylor study [Nonlinearity 13 (2000)] by investigating in different Banach spaces (,c₀(ℕ),c(ℕ)) the point, continuous and residual spectra of stochastic perturbations of the shift operator associated to the stochastic adding machine in base 2 and in the Fibonacci base. For the base 2, the spectra are connected to the Julia set of a quadratic map. In the Fibonacci case, the spectrum is related to the Julia set of an endomorphism of ℂ².
On the spectrum of the analytic generator.