Plasma stability calculations by fast rational approximation

The recently developed AAA (“adaptive Antoulas–Anderson,” pronounced as “triple-A”) algorithm, which rapidly produces an accurate rational approximation, is an extremely effective numerical technique for the plasma physics community. We apply AAA approximation and provide examples of practical use in plasma physics. We show the analytic continuation of the generalized plasma dispersion Z function can be effectively calculated for a variety of distribution functions with the flexibility provided by AAA. Rational function approximation is also applied to the more complicated case in which particle orbits are analytically intractable.