Abstract:
The paper addresses a problem of sampling discretization of integral norms of elements of finite-dimensional subspaces satisfying some conditions. We prove sampling discretization results under two standard kinds of assumptions: conditions on the entropy numbers and conditions in terms of Nikol'skii-type inequalities. We prove some upper bounds on the number of sample points sufficient for good discretization and show that these upper bounds are sharp in a certain sense. Then we apply our general conditional results to subspaces with special structure, namely, subspaces with tensor product structure. We demonstrate that the application of theorems based on Nikol'skii-type inequalities provides somewhat better results than the application of theorems based on entropy numbers conditions. Finally, we apply discretization results to the problem of sampling recovery.
The first named author's research was partially supported by the NSERC (Canada) Discovery grant RGPIN-2020-03909. The second named author's research was supported by the Government of the Russian Federation, grant no. 14.W03.31.0031.
Citation:
F. Dai, V. N. Temlyakov, “Sampling Discretization of Integral Norms and Its Application”, Approximation Theory, Functional Analysis, and Applications, Collected papers. On the occasion of the 70th birthday of Academician Boris Sergeevich Kashin, Trudy Mat. Inst. Steklova, 319, Steklov Math. Inst., Moscow, 2022, 106–119; Proc. Steklov Inst. Math., 319 (2022), 97–109