Videolibrary
RUS  ENG    JOURNALS   PEOPLE   ORGANISATIONS   CONFERENCES   SEMINARS   VIDEO LIBRARY   PACKAGE AMSBIB  
Video Library
Archive
Most viewed videos

Search
RSS
New in collection






Complex Approximations, Orthogonal Polynomials and Applications Workshop
June 11, 2021 11:00–11:25, Sochi
 


Uniformly convergent Fourier series with universal power parts on closed subsets of measure zero

S. V. Khrushchev

Satbayev University

Abstract: Given a closed subset $E$ of Lebesgue measure zero on the unit circle $\mathbb{T}$ there is a function $f$ on $\mathbb{T}$ with uniformly convergent symmetric Fourier series
$$ S_n(f,\zeta)=\sum_{k=-n}^n\hat{f}(k)\zeta^k\underset{\mathbb{T}}{\rightrightarrows} f(\zeta), $$
such that for every continuous function $g$ on $E$, there is a subsequence of partial power sums
$$ S^+_n(f,\zeta)=\sum_{k=0}^n\hat{f}(k)\zeta^k $$
of $f$, which converges to $g$ uniformly on $E$. Here
$$ \hat{f}(k)=\int_{\mathbb{T}}\bar{\zeta}^kf(\zeta)\, dm(\zeta), $$
and $m$ is the normalized Lebesgue measure on $\mathbb{T}$.

Language: English

Website: https://us02web.zoom.us/j/8618528524?pwd=MmxGeHRWZHZnS0NLQi9jTTFTTzFrQT09

* Zoom conference ID: 861 852 8524 , password: caopa
 
  Contact us:
 Terms of Use  Registration to the website  Logotypes © Steklov Mathematical Institute RAS, 2024