Bernstein widths of some classes of functions defined by a self-adjoint operator
Summary: We consider the classes of periodic functions with formal self-adjoint linear differential operators \(W_p(\mathcal L_r)\), which include the classical Sobolev class as its special case. Using the iterative method of Buslaev, we determine with the help of the spectrum of linear differential equations the exact values of Bernstein width of the classes \(W_p(\mathcal L_r)\) in the space \(L_q\) for \(1 < p \leq q < \infty\).
scientific article; zbMATH DE number 5964475