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Kolmogorov Widths of the Besov Classes $B^1_{1,\theta }$ and Products of Octahedra
Yuri V. Malykhinab a Steklov Mathematical Institute of Russian Academy of Sciences, ul. Gubkina 8, Moscow, 119991 Russia
b Laboratory “High-Dimensional Approximation and Applications,” Lomonosov Moscow State University, Leninskie Gory 1, Moscow, 119991 Russia
Abstract:
We find the decay orders of the Kolmogorov widths of some Besov classes related to $W^1_1$ (the behavior of the widths for the class $W^1_1$ remains unknown): $d_n(B^1_{1,\theta }[0,1],L_q[0,1])\asymp n^{-1/2}\log ^{\max \{1/2,1-1/\theta \}}n$ for $2<q<\infty $ and $1\le \theta \le \infty $. The proof relies on the lower bound for the width of a product of octahedra in a special norm (maximum of two weighted $\ell _{q_i}$ norms). This bound generalizes B. S. Kashin's theorem on the widths of octahedra in $\ell _q$.
Received: May 19, 2020 Revised: October 10, 2020 Accepted: October 20, 2020
Citation:
Yuri V. Malykhin, “Kolmogorov Widths of the Besov Classes $B^1_{1,\theta }$ and Products of Octahedra”, Function Spaces, Approximation Theory, and Related Problems of Analysis, Collected papers. In commemoration of the 115th anniversary of Academician Sergei Mikhailovich Nikol'skii, Trudy Mat. Inst. Steklova, 312, Steklov Math. Inst., Moscow, 2021, 224–235; Proc. Steklov Inst. Math., 312 (2021), 215–225
Linking options:
https://www.mathnet.ru/eng/tm4136https://doi.org/10.4213/tm4136 https://www.mathnet.ru/eng/tm/v312/p224
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