Mathematician guys, Could you help me to find below integral?
$$\int_{- \infty}^ {\infty} \frac{\exp(-i k.r) f(k)}{k^4} d^3k$$
I know below definition:
$$\int_{- \infty}^ {\infty} \exp(-i k.r) f(k) d^3k = F(r)$$
I need both cases: 1- f(r) is spherically symmetric 2_ It is symmetric just in x and y-direction. Any answer is highly appreciated.