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5 votes
1 answer
325 views

The discrete Fourier transform's Gaussian-like eigenvector

I have the $N$x$N$ matrix below where $N$ is a power of 2 (usually 64 or 256) and $\omega = 2\pi/N$. What is its largest eigenvalue? $\begin{bmatrix} 2 & 1 & 0 & 0 & \cdots & 0 &...
bobuhito's user avatar
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4 votes
1 answer
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Eigenvalue of a convolution and a restriction?

Let $\epsilon>0$ be small. Let $\eta(t) = \frac{2\epsilon}{\epsilon^2+(2\pi t)^2}$ (the Fourier transform of $x\mapsto e^{-\epsilon |x|}$). Let $V$ be the space of integrable, bounded functions $f:\...
H A Helfgott's user avatar
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