Spectral study of a coupled compact-noncompact problem
Spectral subspaces and non-commutative Hilbert transforms
Let G be a locally compact abelian group and ℳ be a semifinite von Neumann algebra with a faithful semifinite normal trace τ. We study Hilbert transforms associated with G-flows on ℳ and closed semigroups Σ of Ĝ satisfying the condition Σ ∪ (-Σ) = Ĝ. We prove that Hilbert transforms on such closed semigroups satisfy a weak-type estimate and can be extended as linear maps from L¹(ℳ,τ) into . As an application, we obtain a Matsaev-type result for p = 1: if x is a quasi-nilpotent compact operator...
Spectral synthesis and operator synthesis
Relations between spectral synthesis in the Fourier algebra A(G) of a compact group G and the concept of operator synthesis due to Arveson have been studied in the literature. For an A(G)-submodule X of VN(G), X-synthesis in A(G) has been introduced by E. Kaniuth and A. Lau and studied recently by the present authors. To any such X we associate a -submodule X̂ of ℬ(L²(G)) (where is the weak-* Haagerup tensor product ), define the concept of X̂-operator synthesis and prove that a closed set E...
Spectral theory and Cauchy problems on Lp spaces.
Spectral theory and operator ergodic theory on super-reflexive Banach spaces
On reflexive spaces trigonometrically well-bounded operators have an operator-ergodic-theory characterization as the invertible operators U such that . (*) Trigonometrically well-bounded operators permeate many settings of modern analysis, and this note highlights the advances in both their spectral theory and operator ergodic theory made possible by a recent rekindling of interest in the R. C. James inequalities for super-reflexive spaces. When the James inequalities are combined with Young-Stieltjes...
Spectral Theory and Sheaf Theory. II.
Spectral theory and sheaf theory. III.
Spectral theory from the second-order -difference operator.
Spectral theory of corrugated surfaces
We discuss spectral and scattering theory of the discrete laplacian limited to a half-space. The interesting properties of such operators stem from the imposed boundary condition and are related to certain phenomena in surface physics.
Spectral Theory of Generalized Endomorpisms I
Spectral theory of SG pseudo-differential operators on
To every elliptic SG pseudo-differential operator with positive orders, we associate the minimal and maximal operators on , 1 < p < ∞, and prove that they are equal. The domain of the minimal ( = maximal) operator is explicitly computed in terms of a Sobolev space. We prove that an elliptic SG pseudo-differential operator is Fredholm. The essential spectra of elliptic SG pseudo-differential operators with positive orders and bounded SG pseudo-differential operators with orders 0,0 are computed....
Spectral Theory of the Dirac Operator.
Spectral theory of Toeplitz and Hankel operators on the Bergman space .
Spectral trajectories,duality and inductive-projective limits of Hilbert spaces
Spectral transition parameters for a class of Jacobi matrices
This paper initially considers a class of unbounded Jacobi matrices defined by an increasing sequence of repeated weights. Spectral parameters are then introduced in various ways to allow the authors to study the nature and location of the spectrum as a function of these parameters.
Spectral versus classical Nevanlinna-Pick interpolation in dimension two.
Spectral well-behaved *-representations
In this brief account we present the way of obtaining unbounded *-representations in terms of the so-called "unbounded" C*-seminorms. Among such *-representations we pick up a special class with "good behaviour" and characterize them through some properties of the Pták function.
Spectrality Criteria for Unbounded Operators with Real Spectrum.
Spectraloid operator polynomials, the approximate numerical range and an Eneström-Kakeya theorem in Hilbert space
We study a class of operator polynomials in Hilbert space which are spectraloid in the sense that spectral radius and numerical radius coincide. The focus is on the spectrum in the boundary of the numerical range. As an application, the Eneström-Kakeya-Hurwitz theorem on zeros of real polynomials is generalized to Hilbert space.
Spectre conjoint d'opérateurs pseudo-différentiels qui commutent.