Brian Wilson

Spin-orbit interaction effects on the Rosseland mean opacity

Recently published opacity tables for astrophysical mixtures using the OPAL code showed significant differences when compared to the commonly used Los Alamos results. An important finding of the OPAL calculations was a large opacity enhancement (approximately factors of 3) in the few hundred-thousand degree temperature range. This new opacity bump is a consequence of improvements in the atomic data generation

Umbral calculus and the theory of multispecies non-ideal gases

Relations in the cluster expansion theory of non-ideal gases are presented using the recently developed formalism of umbral calculus. This paper provides an overview of the mathematical theory and explicitly derives the virial expansion and relations between the partition function and reducible and irreducible cluster coefficients for single and multispecies non-ideal gases. It is shown that these results are obtained remarkably easily using the methods of umbral calculus.

Reply to “Comment on ‘Accurate and fast numerical solution of Poisson's equation for arbitrary, space-filling Voronoi polyhedra: Near-field corrections revisited’ ”

This is a Reply to the Comment by Gonis and Zhang1 on our recent paper.2 They discuss supposed issues with our “accurate and fast numerical solution of Poisson’s equation for arbitrary Voronoi polyhedra” (VP). The method of Gonis et al.3 and Vitos and Koll´ar4 correctly addresses the mathematical issues related to the solution of Poisson’s equation [and near-field corrections (NFCs)] using a spherical harmonic basis (L’s). However, as discussed in Ref. 2, their method is not numerically efficient and suffers from severe convergence issues from the multiply nested (conditionally convergent) multipole expansions to address r problems. Hence, the abstract in Ref. 2 clearly states that we provide a method to address a “fast but accurate numerical solution of the Poisson equation” for site-centered methods.