The Fourier transform of multiradial functions

Abstract: We obtain an exact formula for the Fourier transform of multiradial functions, i.e., functions of the form $\Phi(x)=\phi(|x_1|, \dots, |x_m|)$, $x_i\in \mathbf R^{n_i}$, in terms of the Fourier transform of the function $\phi$ on $$\mathbf R^{r_1}\times \cdots \times \mathbf R^{r_m}$$, where $r_i$ is either 1 or 2.