Mityagin's extension problem. Progress report

Autor: Alexander Goncharov, Zeliha Ural
Rok vydání: 2017
Předmět:
Zdroj: Journal of Mathematical Analysis and Applications
ISSN: 0022-247X
DOI: 10.1016/j.jmaa.2016.11.001
Popis: Given a compact set K subset of R-d, let epsilon(K) denote the space of Whitney jets on K. The compact set K is said to have the extension property if there exists a continuous linear extension operator W : epsilon(K) -> C infinity (R-d). In 1961 B.S. Mityagin posed a problem to give a characterization of the extension property in geometric terms. We show that there is no such complete description in terms of densities of Hausdorff contents or related characteristics. Also the extension property cannot be characterized in terms of growth of Markov's factors for the set. (C) 2016 Elsevier Inc. All rights reserved.
Databáze: OpenAIRE