The spectral radii of an operator and its modulus
The spectrally bounded linear maps on operator algebras
We show that every spectrally bounded linear map Φ from a Banach algebra onto a standard operator algebra acting on a complex Banach space is square-zero preserving. This result is used to show that if Φ₂ is spectrally bounded, then Φ is a homomorphism multiplied by a nonzero complex number. As another application to the Hilbert space case, a classification theorem is obtained which states that every spectrally bounded linear bijection Φ from ℬ(H) onto ℬ(K), where H and K are infinite-dimensional...
The spectrum and commutant of a certain weighted translation operator.
The spectrum band structure of the three-dimensional Schrödinger operator with periodic potential.
The spectrum of a class of almost periodic operators.
The Spectrum Of Infinite Complite Multipartite Graphs
The spectrum of Schrödinger operators with random magnetic fields
We shall consider the Schrödinger operators on with the magnetic field given by a nonnegative constant field plus random magnetic fields of the Anderson type or of the Poisson-Anderson type. We shall investigate the spectrum of these operators by the method of the admissible potentials by Kirsch-Martinelli. Moreover, we shall prove the lower Landau levels are infinitely degenerated eigenvalues when the constant field is sufficiently large, by estimating the growth order of the eigenfunctions...
The Spectrum of the Continuous Laplacian on a Graph.
The spectrum of the discrete Cesàro operator
The spectrum of the transport operator with a potential term under the spatial periodicity condition
The splitting spectrum differs from the Taylor spectrum
We construct a pair of commuting Banach space operators for which the splitting spectrum is different from the Taylor spectrum.
The squares of the Laplacian-Dirichlet eigenfunctions are generically linearly independent
The paper deals with the genericity of domain-dependent spectral properties of the Laplacian-Dirichlet operator. In particular we prove that, generically, the squares of the eigenfunctions form a free family. We also show that the spectrum is generically non-resonant. The results are obtained by applying global perturbations of the domains and exploiting analytic perturbation properties. The work is motivated by two applications: an existence result for the problem of maximizing the rate of...
The stability of tachyonic field system by factorization method.
The Stability of the Euler Characteristic for Hilbert Complexes.
The stability radius of a bundle of closed linear operators
The stability radius of an operator of Saphar type
A bounded linear operator T on a complex Banach space X is called an operator of Saphar type if its kernel is contained in its generalized range and T is relatively regular. For T of Saphar type we determine the supremum of all positive numbers δ such that T - λI is of Saphar type for |λ| < δ.
The stationary exterior 3 D-problem of Oseen and Navier-Stokes equations in anisotropically weighted Sobolev spaces.
The stationary phase method in Gevrey classes and Fourier integral operators on ultradistributions
The strong unicity constant and its applications
In this report we discuss the applications of the strong unicity constant and highlight its use in the minimal projection problem.
The strong unicity constant for projections.