标题： 差分的合成算子的逼近数 显示英文标题

标题： Approximation numbers of differences of composition operators

摘要： 在本研究中，我们考虑作用于Hardy-Hilbert空间H 2 (D)上的复合算子差的逼近数。 我们得到了这些逼近数的上界和下界，并通过将这些一般结果应用于具有特定类型符号的复合算子，我们展示了边界行为对逼近数的影响。 此外，我们使用这些一维方法和例子来理解作用于双圆盘空间H 2 (D 2 )上的复合算子差的逼近数。 显示英文摘要

摘要： In this study we consider the approximation numbers of differences of composition operators acting on the Hardy-Hilbert space H 2 (D). We obtain both upper and lower bounds for these approximation numbers and by applying these general results to composition operators with specific types of symbols, we demonstrate the effect of boundary behaviour over the approximation numbers. Moreover, we use these one-dimensional methods and examples to understand the approximation numbers of differences of composition operators acting on the space H 2 (D 2 ) of the bidisc.