Analysis seminar
Speaker: Adrian Ubis (Hebrew University)

Title:  Smoothness of Fourier series with polynomial frequencies
Date: Thursday, April 19 at 2:30 p.m.
Place: Amado 919.
Cookies: 10 minutes before the talk
Abstract: Let F be the 1-periodic function defined as F(x)=x for
|x|<1/2.Let P(t) be any non-linear polynomial with integer
Consider the 1-periodic function F_P defined by
keeping just the Fourier coefficients of F whose
frequencies are of the shape P(n) with n an integer.
We will show that the smoothness properties of this function
are quite complex in the sense that for each s in some interval,
the points with Holder exponent s form a set of positive Hausdorff
This was previously known for P a quadratic polynomial,
namely for Riemann's example of a continuous but almost nowhere
differentiable function.
Seminar webpage:  <>
Technion Math. Net (TECHMATH)
Editor: Michael Cwikel   <> 
Announcement from: Tamar Ziegler   <>