Abstract
In this study, the estimates of approximation numbers of embedding operators in weighted spaces have been analyzed. These estimates depend on orders of differential operators, dimensions of function spaces and weighted functions. This fact implies that the associated embedding operators belong to Schatten class of compact operators. By using these estimates, the discreetness of spectrum and completion of root elements relating to principal nonselfedjoint degenerate differential operators is obtained.
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Shakhmurov, V. Estimates of approximation numbers and applications. Acta. Math. Sin.-English Ser. 28, 1883–1896 (2012). https://doi.org/10.1007/s10114-012-9547-y
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DOI: https://doi.org/10.1007/s10114-012-9547-y
Keywords
- Approximation numbers
- Kolmogorov numbers
- separable boundary value problems
- differential-operator equations
- Banach-valued function spaces
- operator-valued multipliers
- interpolation of Banach spaces