Radiative conductivity
= Radiative conductivity
{title2=$\chi=4acT^3/(3\kappa\rho)$}
In the optically thick <radiative diffusion in a star> approximation, the heat flux is $\mathbf F=-\chi\nabla T$. The conductivity depends on <opacity>, <mass density> and <temperature>. It relates a material temperature gradient to energy transport and must not be confused with the emergent <effective temperature>.