Seismic Inference Using Genetic Algorithms

Abstract

A flood of reliable seismic data will soon arrive. The migration to larger telescopes on the ground may free up 4-m class instruments for multi-site campaigns, and several forthcoming satellite missions promise to yield nearly uninterrupted long-term coverage of many pulsating stars. We will then face the challenge of determining the fundamental properties of these stars from the data, by trying to match them with the output of our computer models. The traditional approach to this task is to make informed guesses for each of the model parameters, and then adjust them iteratively until an adequate match is found. The trouble is: how do we know that our solution is unique, or that some other combination of parameters will not do even better? Computers are now sufficiently powerful and inexpensive that we can produce large grids of models and simply compare all of them to the observations. The question then becomes: what range of parameters do we want to consider, and how many models do we want to calculate? This can minimize the subjective nature of the process, but it may not be the most efficient approach and it may give us a false sense of security that the final result is correct, when it is really just optimal. I discuss these issues in the context of recent advances in the asteroseismological analysis of white dwarf stars.