Abstract
Order estimates are obtained for the Kolmogorov, linear, and Gel’fand widths of the image of the unit ball of the space l p under the action of a two-weight summation operator with weights of special kind. Some limit conditions on the parameters defining the weights are considered.
Similar content being viewed by others
References
G. Bennett, “Some elementary inequalities. III, ” Q. J. Math. Oxford, Ser.2, 42 (166), 149–174 (1991).
D. E. Edmunds and J. Lang, “Approximation numbers and Kolmogorov widths of Hardy-type operators in a non-homogeneous case, ” Math. Nachr. 297 (7), 727–742 (2006).
W. D. Evans, D. J. Harris, and J. Lang, “The approximation numbers of Hardy-type operators on trees, ” Proc. London Math. Soc., Ser. 3, 83 (2), 390–418 (2001).
A. Yu. Garnaev and E. D. Gluskin, “On widths of the Euclidean ball, ” Dokl. Akad. Nauk SSSR 277 (5), 1048–1052 (1984) [Sov. Math., Dokl. 30, 200–204 (1984)].
E. D. Gluskin, “Norms of random matrices and widths of finite-dimensional sets, ” Mat. Sb. 120 (2), 180–189 (1983) [Math. USSR, Sb. 48, 173–182 (1984)].
D. D. Haroske and L. Skrzypczak, “Entropy and approximation numbers of embeddings of function spaces with Muckenhoupt weights. I, ” Rev. Mat. Complut. 21 (1), 135–177 (2008).
D. D. Haroske and L. Skrzypczak, “Entropy and approximation numbers of embeddings of function spaces with Muckenhoupt weights. II: General weights, ” Ann. Acad. Sci. Fenn., Math. 36 (1), 111–138 (2011).
B. S. Kashin, “On Kolmogorov diameters of octahedra, ” Dokl. Akad. Nauk SSSR 214 (5), 1024–1026 (1974) [Sov. Math., Dokl. 15, 304–307 (1974)].
B. S. Kashin, “The diameters of octahedra, ” Usp. Mat. Nauk 30 (4), 251–252 (1975).
B. S. Kashin, “Diameters of some finite-dimensional sets and classes of smooth functions, ” Izv. Akad. Nauk SSSR, Ser. Mat. 41 (2), 334–351 (1977) [Math. USSR, Izv. 11, 317–333 (1977)].
M. A. Lifshits, “Bounds for entropy numbers for some critical operators, ” Trans. Am. Math. Soc. 364 (4), 1797–1813 (2012).
M. A. Lifshits and W. Linde, Approximationand Entropy Numbers of Volterra Operators with Application to Brownian Motion (Am. Math. Soc., Providence, RI, 2002), Mem. AMS 157 (745).
M. Lifshits and W. Linde, “Compactness properties of weighted summation operators on trees, ” Stud. Math. 202 (1), 17–47 (2011).
M. Lifshits and W. Linde, “Compactness properties of weighted summation operators on trees—the critical case, ” Stud. Math. 206 (1), 75–96 (2011).
E. N. Lomakina and V. D. Stepanov, “On asymptotic behaviour of the approximation numbers and estimates of Schatten–von Neumann norms of the Hardy-type integral operators, ” in Function Spaces and Applications: Proc. Int. Conf., New Delhi, 1997 (Narosa Publ. House, New Delhi, 2000), pp. 153–187.
E. N. Lomakina and V. D. Stepanov, “Asymptotic estimates for the approximation and entropy numbers of a one-weight Riemann–Liouville operator, ” Mat. Tr. 9 (1), 52–100 (2006) [Sib. Adv. Math. 17 (1), 1–36 (2007)].
A. Pietsch, “s-Numbers of operators in Banach spaces, ” Stud. Math. 51, 201–223 (1974).
A. I. Stepanets, Methodsof Approximation Theory (Koninklijke Brill NV, Leiden, 2005).
M. I. Stesin, “Aleksandrov diameters of finite-dimensional sets and classes of smooth functions, ” Dokl. Akad. Nauk SSSR 220 (6), 1278–1281 (1975) [Sov. Math., Dokl. 16, 252–256 (1975)].
V. M. Tikhomirov, “Diameters of sets in function spaces and the theory of best approximations, ” Usp. Mat. Nauk 15 (3), 81–120 (1960) [Russ. Math. Surv. 15 (3), 75–111 (1960)].
A. A. Vasil’eva, “Widths of weighted Sobolev classes on a John domain: Strong singularity at a point, ” Rev. Mat. Complut. 27 (1), 167–212 (2014).
A. A. Vasil’eva, “Widths of function classes on sets with tree-like structure, ” J. Approx. Theory 192, 19–59 (2015).
A. A. Vasil’eva, “Widths of Sobolev weight classes on a domain with cusp, ” Mat. Sb. 206 (10), 37–70 (2015) [Sb. Math. 206, 1375–1409 (2015)].
A. A. Vasil’eva, “Estimates for n-widths of two-weighted summation operators on trees, ” Math. Notes 99, 243–252 (2016).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © A.A. Vasil’eva, 2016, published in Trudy Matematicheskogo Instituta imeni V.A. Steklova, 2016, Vol. 294, pp. 308–324.
Rights and permissions
About this article
Cite this article
Vasil’eva, A.A. Estimates for the widths of discrete function classes generated by a two-weight summation operator. Proc. Steklov Inst. Math. 294, 291–307 (2016). https://doi.org/10.1134/S0081543816060201
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0081543816060201