Аннотация:
We obtain two–sided estimates which describe the behaviour of the approximation numbers of the Hardy operator and Schatten–Neumann norms in the new case, when the compact operator
$$
Tf(x)=\int_0^x f(\tau) d\tau, \quad x>0,
$$
is acting from a Lebesgue space to a Lorentz space $(T: L_v^r(R^+)\to L_\omega^{pq}(R^+))$ under the
condition $1<p<r\leqslant q<\infty$.
Ключевые слова и фразы:Lebesgue space, Lorentz space, Hardy operator, approximation numbers, Schatten–von Neumann norm.