BISTABILITY AND COMPETITION OF SPATIOTEMPORAL CHAOTIC AND FIXED-POINTATTRACTORS IN RAYLEIGH-BENARD CONVECTION

For Rayleigh-Benard convection in a square cell with a fluid of Prandt l number sigma approximate to 1, we report experimental results on the bistability of the spatiotemporal chaotic state of spiral defect chao s (SDC) and a stationary state of ideal straight rolls (ISR). We prese nt the first large aspect ratio experimental confirmation of the theor etical prediction of stable ISR in the parameter regime where typical initial conditions lead to SDC. As a function of the control parameter and for typical experimental initial conditions, we also find a trans ition in the selection between SDC and ISR which is mediated by front propagation. We characterize the transition with two measures, the spa tial correlation length and the spectral pattern entropy, and find tha t the transition shows similarities to equilibrium phase transitions.