Not sure if this question has been previously asked, but why the PDF of rice distribution contain the Bessel function:
$$ f(x \mid \nu, \sigma)=\frac{x}{\sigma^2} \exp \left(\frac{-\left(x^2+\nu^2\right)}{2 \sigma^2}\right) I_0\left(\frac{x \nu}{\sigma^2}\right) $$
Is there any intuitive or logical reasoning behind having a Bessel function of zero-kind?