Abstract:
A new notion of weak monotonicity of sets is introduced, and it is shown that an approximatively compact and weakly monotone connected (weakly Menger-connected) set in a Banach space admits a continuous additive (multiplicative) $\varepsilon $-selection for any $\varepsilon >0$. Then a notion of weak monotone connectedness (weak Menger connectedness) of sets with respect to a set of $d$-defining functionals is introduced. For such sets, continuous $(d^{-1},\varepsilon )$-selections are constructed on arbitrary compact sets.
Citation:
I. G. Tsar'kov, “Weakly monotone sets and continuous selection from a near-best approximation operator”, Harmonic analysis, approximation theory, and number theory, Collected papers. Dedicated to Academician Sergei Vladimirovich Konyagin on the occasion of his 60th birthday, Trudy Mat. Inst. Steklova, 303, MAIK Nauka/Interperiodica, Moscow, 2018, 246–257; Proc. Steklov Inst. Math., 303 (2018), 227–238
\Bibitem{Tsa18}
\by I.~G.~Tsar'kov
\paper Weakly monotone sets and continuous selection from a near-best approximation operator
\inbook Harmonic analysis, approximation theory, and number theory
\bookinfo Collected papers. Dedicated to Academician Sergei Vladimirovich Konyagin on the occasion of his 60th birthday
\serial Trudy Mat. Inst. Steklova
\yr 2018
\vol 303
\pages 246--257
\publ MAIK Nauka/Interperiodica
\publaddr Moscow
\mathnet{http://mi.mathnet.ru/tm3947}
\crossref{https://doi.org/10.1134/S0371968518040180}
\mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=3918866}
\elib{https://elibrary.ru/item.asp?id=37045265}
\transl
\jour Proc. Steklov Inst. Math.
\yr 2018
\vol 303
\pages 227--238
\crossref{https://doi.org/10.1134/S0081543818080187}
\isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=000460475900018}
\scopus{https://www.scopus.com/record/display.url?origin=inward&eid=2-s2.0-85062544600}
Linking options:
https://www.mathnet.ru/eng/tm3947
https://doi.org/10.1134/S0371968518040180
https://www.mathnet.ru/eng/tm/v303/p246
This publication is cited in the following 2 articles:
A. R. Alimov, “Vypuklost i monotonnaya lineinaya svyaznost mnozhestv s nepreryvnoi metricheskoi proektsiei v trekhmernykh prostranstvakh”, Tr. IMM UrO RAN, 26, no. 2, 2020, 28–46
I. G. Tsar'kov, “Local Approximation Properties of Sets and Continuous Selections on Them”, Math. Notes, 106:6 (2019), 995–1008