Titlebook: Recent Progress in Operator Theory; International Worksh I. Gohberg,R. Mennicken,C. Tretter Conference proceedings 1998 Springer Basel AG 1

祖?zhèn)?/a>

The sum of matrix nevanlinna functions and self-adjoint extensions in exit spaces,s. Our interest is in self-adjoint extensions of a symmetric relation which extends itself an orthogonal sum of two symmetric relations. The corresponding class of parameters in Kre 137-2 n’s formula is idcntificd. This leads to a description of (minimal) self-adjoint extensions in a fixed exit spac

俗艷

,Properties of “derived” Hankel matrices,her order. Such matrices will be called .. The main results are a generalization of Kronecker’s Theorem, Vandermonde factorization of infinite finite-rank derived Hankel matrices, description of their range, rank and signature, and inversion of finite triangular derived Hankel matrices. A definition

Frisky

支柱

Fredholm theory of interpolation morphisms, T as an interpolation morphism is studied and the results are applied to the real interpolation method. In this application it is shown that, whenever ..,. is a Fredholm operator (for some 0 < Θ. < 1 and 1 ≤ . < ∞) then .Θ,. is a Fredholm operator for all Θ in a neighborhood of Θ. and all 1 ≤ . < ∞

分期付款

Resolvents of symmetric sperators and the degenerated Nevanlinna-Pick problem,ric operator . in . with defect index (1,1). We give a parametrization of the ?traus extensions of . acting in a Pontryagin space .of dimension . + 1 and of negative index 1, and a parametrization of the corresponding set of .-resolvents of .. These results are applied to a classical Nevanlinna-Pick

不適當(dāng)

遵循的規(guī)范

Demonstrate

Insatiable

Fredholm theory of interpolation morphisms,r ..,. is a Fredholm operator (for some 0 < Θ. < 1 and 1 ≤ . < ∞) then .Θ,. is a Fredholm operator for all Θ in a neighborhood of Θ. and all 1 ≤ . < ∞ and the null space and the deficiency of these operators are constant.

倒轉(zhuǎn)

On nonnegative realizations of rational matrix functions and nonnegative input-output systems, and the latter is less than or equal to the minimum of the number of extreme rays of polyhedral cones .. with the properties mentioned above. We give an example for which both these inequalities are strict.