The Gauss Weierstrass kernel \(\psi_{\kappa}\in L^2(\mathcal{SO}(3))\) is a nonnegative function depending on a parameter \(\kappa>0\) and is defined by its Chebyshev series
\[ \psi_{\kappa}(t) = \sum\limits_{n=0}^{\infty} (2n+1) \, \mathrm e^{-n(n+1)\kappa} \, \mathcal U_{2n}(t)\].
Syntax
psi = SO3GaussWeierstrassKernel(0.1)