## Smoothness of Fourier series with polynomial frequencies

Type:
Site:
Date:
17/01/2013 - 11:00 - 12:00
Salle:
I1-223
Orateur:
Let $P$ be any non-linear polynomial with integer coefficients. Consider the function defined by keeping just the Fourier coefficients of the ”fractional part” function whose frequencies are of the shape $P(n)$ with $n$ a natural number.
This had been previously shown by S. Jaffard for $P$ a quadratic polynomial, namely for Riemann’s example of a continuous but almost nowhere differentiable function.