## Approximation numbers and entropy numbers of embeddings of fractional Besov-Sobolev spaces in Orlicz spaces.(English)Zbl 0792.46024

Let $$\Omega$$ be a bounded $$C^ \infty$$ domain in $$\mathbb{R}^ n$$. The paper deals with the approximation numbers and entropy numbers of the compact embeddings of the limiting spaces $$H^{n/p}_ p(\Omega)$$ and $$B^{n/p}_ p(\Omega)$$ of Besov-Sobolev type into appropriate Orlicz spaces of Trudinger type.
Reviewer: H.Triebel (Jena)

### MSC:

 46E35 Sobolev spaces and other spaces of “smooth” functions, embedding theorems, trace theorems 47B06 Riesz operators; eigenvalue distributions; approximation numbers, $$s$$-numbers, Kolmogorov numbers, entropy numbers, etc. of operators 46E30 Spaces of measurable functions ($$L^p$$-spaces, Orlicz spaces, Köthe function spaces, Lorentz spaces, rearrangement invariant spaces, ideal spaces, etc.)
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