Bounds on Fourier coefficients of Euclidean distance functions

106 Views Asked by At

I am interested in the bounding the Fourier coefficients $a_{m,n}$ of the function $f(x,y)=\sqrt{x^2+y^2}$ defined on the interval $[-1,1]^2$. I am specifically interested in understanding the behavior of the coefficients asymptotically in terms of $m,n\in\mathbb{Z}$. I attempted to consider the explicit expression for the Fourier coefficients but the integrals involving $f(x,y)$ become nontrivial to evaluate. Any suggestions?