О некоторых числах оператора Харди в пространствах Лоренца |
Е.Н. Ломакина, М.Г. Насырова, В.В. Насыров |
2021, выпуск 1, С. 71–88 DOI: https://doi.org/10.47910/FEMJ202107 |
Аннотация |
В статье доказан критерий компактности оператора $Tf(x)=\int_0^x u(\tau) f(\tau)v(\tau)\,d\tau,$ $x>0,$ действующего в весовых пространствах Лоренца $T:L^{r,s}_{v}(\mathbb{R^+})\to L^{p,q}_{\omega}(\mathbb{R^+})$ в области $1<\max (r,s)\le q<\infty$, $1 |
Ключевые слова: интегральный оператор Харди, компактный оператор, пространства Лоренца, аппроксимативные числа, числа Гельфанда, числа Колмогорова, числа Бернштейна, числа Митягина, энтропийные числа |
Полный текст статьи (файл PDF) |
Библиографический список |
[1] C. Bennett, R. Sharpley, Interpolation of Operators. V. 129, Pure and Applied Mathematics, Academic Press, Boston, 1988. [2] А. Пич, Операторные идеалы, Мир, М., 1982. [3] S. Barza, V. Kolyada V., J. Soria, “Sharp constants related to the triangle inequality in Lorentz spaces”, Trans. Amer. Math. Soc., 361:10 (2009), 5555–5574. [4] H. Konig, Eigenvalue distribution of compact operators. V. 16, Operator Theory: Advances and Applications, Birkh?auser Verlag, Basel, 1986. [5] D.E. Edmunds, W.D. Evans, Spectral theory and differential operators, Oxford Mathematical Monographs, Oxford University Press, Oxford, 1987. [6] B. Carl, I. Stephani, Entropy, compactness and the approximation of operators, Cambridge Univ. Press., Cambridge, 1990. [7] D.E. Edmunds, W. D. Evans, D. J. Harris, “Approximation numbers of certain Volterra integral operators”, London Math. Soc. (2), 38 (1988), 471–489. [8] D.E. Edmunds, V. Stepanov, “On singular numbers of certain Volterra integral operators”, J. Funct. Anal., 134 (1995), 222–246. [9] D.E. Edmunds, W.D. Evans, D. J. Harris, “Two-sided estimates of the approximation numbers of certain Volterra integral operators”, Studia Math. (1), 124 (1997), 59–80. [10] E. Lomakina, V. Stepanov, “On asymptotic behaviour of the approximation numbers and estimates of Schatten von Neumann norms of the Hardy–type integral operators”, Function spaces and application, 2000, 153–187. [11] M.A. Lifshits, W. Linde, “Approximation and entropy numbers of Volterra operators with application to Brownian motion”, Mem. Am. Math. Soc., 745 (2002.), 1–87. [12] E. Lomakina, V. Stepanov, “On the compactness and approximation numbers of Hardy type integral operators in Lorentz spases”, J. London Math. Soc. (2), 53 (1996), 369–382. [13] E. Lomakina, V. Stepanov, “On the Hardy-type integral operators in Banach function spases”, Publicacions Matematiques, 42 (1998), 165–194. [14] Е.Н. Ломакина, “ Об оценках норм оператора Харди, действующего в пространствах Лоренца”, Дальневосточ. матем. журн., 20:2 (2020), 191–211. [15] E.T. Sawyer, “Weighted Lebesgue and Lorentz norm inequalities for the Hardy operator”, Trans. Amer. Math. Soc., 281 (1984), 329–337. [16] A. Pietsch, “s-Numbers of operators in Banach spaces”, Studia Math., 51 (1974), 201–223. |