Title: Chaos in the Music of the Stars
Speaker: Robert Buchler
Speaker Info: University of Florida
Brief Description:
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Abstract:
In contrast to the well-known classical Cepheid variable stars, which undergo pulsations with clocklike regularity, some large-amplitude pulsating stars exhibit a highly irregular oscillatory behavior. The nature of these irregular pulsations remained a mystery for a long time. We analyze the observational data with a general method of modern nonlinear dynamics, namely a flow reconstruction in phase space. The underlying dynamics is shown to be chaotic, and of a surprisingly low dimension of 4. We also present the results of numerical hydrodynamic simulations that show cascades of period doubling and chaos in models for these stars. We conclude with the physical insight one can gain from this analysis.Date: Friday, May 13, 2005