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Caltech

Mathematics Colloquium

Tuesday, January 22, 2019
4:00pm to 5:00pm
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Linde Hall 310
Approximate polynomials, higher order Fourier analysis and
Frederick Manners, Department of Mathematics, Stanford University ,

Suppose a function $\{1,\dots,N\} \to \mathbb R$ has the property that when we take discrete derivatives $k$ times, the result is identically zero. It is fairly well-known that this is equivalent to being a polynomial of degree $k-1$. It's not too unnatural to ask: what does the function look like if, instead, the iterated derivative is required to be zero just a positive proportion of the time? Such \emph{approximate polynomials} have a richer structure, related to nilpotent Lie groups.

On an unrelated note: given an $n \times n$ chessboard, how many ways are there to arrange $n$ queens on it, so that no two attack each other?

I'll outline how both these questions are connected to what's known as \emph{higher order Fourier analysis}, and explain more generally what higher order Fourier analysis is and what it can be used for (other than potentially placing queens on chessboards).

For more information, please contact Mathematics Department by phone at 4335 or by email at [email protected].