# Fourrier transform of cos

1. May 29, 2014

### kd6ac

Fourier transform of density matrix of cos(x+y)*cos(x-y)

I would like to know whether there exists a solution to the following integral,

$$\frac{1}{\pi} \int\limits_{-\infty}^{\infty} \cos(x+y)^\alpha \cos(x-y)^\alpha e^{2ipy}$$

The above expression is the Fourier transform of the off-diagonal elements of the density matrix,

$$\rho = \cos(x+y)^\alpha \cos(x-y)^\alpha$$

Any advice, or reference to books/articles, would be greatly appreciated.

Last edited: May 29, 2014
2. May 29, 2014

### mathman

Start by defining the domain for α.
Google "Fourier integral tables" should help.

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