Gantmacher–Kreĭn theorem for 2 nonnegative operators in spaces of functions.
Gâteaux derivative and orthogonality in -classes.
Gâteaux derivative and orthogonality in -classes.
Gelfand and Kolmogorov numbers of embedding of radial Besov and Sobolev spaces
We prove asymptotic formulas for the behavior of Gelfand and Kolmogorov numbers of Sobolev embeddings between Besov and Triebel-Lizorkin spaces of radial distributions. Our method works also for Weyl numbers.
Gelfand numbers and metric entropy of convex hulls in Hilbert spaces
For a precompact subset K of a Hilbert space we prove the following inequalities: , n ∈ ℕ, and , k,n ∈ ℕ, where cₙ(cov(K)) is the nth Gelfand number of the absolutely convex hull of K and and denote the kth entropy and kth dyadic entropy number of K, respectively. The inequalities are, essentially, a reformulation of the corresponding inequalities given in [CKP] which yield asymptotically optimal estimates of the Gelfand numbers cₙ(cov(K)) provided that the entropy numbers εₙ(K) are slowly...
Gelfand numbers of operators with values in a Hilbert space.
General results on the eigenvalues of operators with gaps, arising from both ends of the gaps. Application to Dirac operators
This paper is concerned with an extension and reinterpretation of previous results on the variational characterization of eigenvalues in gaps of the essential spectrum of self-adjoint operators. We state two general abstract results on the existence of eigenvalues in the gap and a continuation principle. Then these results are applied to Dirac operators in order to characterize simultaneously eigenvalues corresponding to electronic and positronic bound states.
General theorems of Mazur-Orlicz type
Generalisation of Rellich's Theorem on Perturbation of (Essentially) Selfadjoin Operators.
Generalization of the Mercer Theorem
Generalization of the Newman-Shapiro isometry theorem and Toeplitz operators. II
The Newman-Shapiro Isometry Theorem is proved in the case of Segal-Bargmann spaces of entire vector-valued functions (i.e. summable with respect to the Gaussian measure on ℂⁿ). The theorem is applied to find the adjoint of an unbounded Toeplitz operator with φ being an operator-valued exponential polynomial.
Generalization of Weyl-von Neumann-Berg theorem for the case of normal operator-valued holomorphic functions
Generalizations of Kaplansky's Theorem Involving Unbounded Linear Operators
We are mainly concerned with the result of Kaplansky on the composition of two normal operators in the case in which at least one of the operators is unbounded.
Generalizations of Mercer's theorem for a class of nonselfadjoint operators
Generalizations of the results on powers of -hyponormal operators.
Generalized Analytic and Quasi-Analytic Vectors
For every sequence (aₙ) of positive real numbers and an operator acting in a Banach space, we introduce the families of (aₙ)-analytic and (aₙ)-quasi-analytic vectors. We prove various properties of these families.
Generalized Cesàro operators on certain function spaces
Motivated by some recent results by Li and Stević, in this paper we prove that a two-parameter family of Cesàro averaging operators is bounded on the Dirichlet spaces . We also give a short and direct proof of boundedness of on the Hardy space for 1 < p < ∞.
Generalized concentrative mappings and their fixed points
Generalized derivation modulo the ideal of all compact operators.
Generalized derivations and bilocal Jordan derivations of nest algebras.