Linear Operators and Approximation / Lineare Operatoren und Approximation -

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Résumé :
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Sommaire:
I. Operator Theory.- Generalizations of Landau's inequality.- Semi-groups of nonlinear transformations.- Singular perturbations of semi-group generators.- Cyclic vectors and commutants.- Some applications of operator valued analytic functions of two complex variables.- Weyl's theorems.- Some approximation problems in the theory of stationary processes.- Ein Operatorenkalk?l f?r das approximationstheoretische Verhalten des Ergodensatzes im Mittel..- A note on the Landau-Kallmann-Rota-Hille inequality.- II. Topics in Functional Analysis.- Representation theorems for Riesz spaces.- Boundedness from measure theory.- Exchange of infinite summation with limits in Banach spaces.- Finite parts of distributions.- Courants et courants cylindriques sur des vari?t?s de dimension infinie.- Subdefinite functions.- Eine Bemerkung zum Banachschen Fixpunktsatz..- On a certain converse of H?lder's inequality.- III. Approximation in Abstract Spaces.- On some geometric properties of the unit sphere.- Diskrete Konvergenz linearer Operatoren III.- On set-valued metric projections.- On the comparison of approximation processes in Hubert spaces.- S?tze vom Jackson-Typ auf Darstellungsr?umen kompakter, zusammenh?ngender Liegruppen.- Approximation d'espaces de fonctions C? et interpolation.- Nonlinear transformations with the conservation of differential properties of functions.- Positive and monotone approximation.- S?tze vom Bohmann-Korowkin-Typ f?r Banachsche Funktionenr?ume.- IV. Harmonic Analysis and Approximation.- Projection m?trique de L1 (T) sur des sous-espaces ferm?s invariants par translation.- Bases dans H1 et bases de sous-espaces de dimension finie dans A.- Logarithmic and exponential variants of Bernstein's inequality and generalized derivatives.- Fourier multipliers whose multiplier norm is an attained value.- Nikolsk? constants for positive singular integrals of perturbed Fej?r-type.- A pointwise o saturation theorem for positive convolution operators.- Convolution operators for Fourier-Jacobi expansions.- V. Spline- and Algebraic Approximation.- Cardinal interpolation and spline functions IV. The exponential Euler splines.- ?????????? ???????? ? ?????? ??????????? (Anwendungen von Splines in der Approximationstheorie) 419.- The fundamental theorem of algebra for monosplines with multiplicities.- A contribution to the problem of weighted polynomial approximation.- Zur Konvergenz der Stufenpolynome ?ber den Nullstellen der Legendre-Polynome.- Chebyshev semi-discrete approximations for linear parabolic problems.- On the convergence theory of Pad? approximants.- Singular self-adjoint multipoint boundary value problems: Solutions and approximations.- ?ber die Konvergenz von nat?rlichen interpolierenden Splines.- New and Unsolved Problems.- Alphabetical List of Papers.