seminar: Stochastic bifurcation in random dynamical systems and its application to modeling fluids and atmospheric dynamics
speaker: Yuzuru Sato (RIES/Department of Mathematics, Hokkaido University)abstract: We study noise-induced phenomenon in terms of stochastic bifurcation in random dynamical systems. Based on the phenomenology of low dimensional random dynamical systems, we investigate techniques for time series analysis and modeling on systems featuring a large number of degrees of freedom. We report the experimental evidence of the existence of a random strange attractor in a turbulent swirling flow. By defining a global observable which tracks the asymmetry in the flux of angular momentum imparted to the flow, we can first reconstruct the associated attractors and then follow its bifurcation route to chaos. We further show that the experimental attractor can be modeled by stochastic Duffing equations, that match the quantitative properties of the experimental flow. Time series analysis and modeling on atmospheric jet dynamics is also presented as another example.
Reference: D. Faranda, Y. Sato, B. Saint-Michel, C. Wiertel, V. Padilla, B. Dubrulle, and F. Daviaud, Phys. Rev. Lett. 119, 014502, 2017.
DOI:https:/doi.org10.1103PhysRevLett.119.014502
timetable:
Wed 3 Oct, 14:30 - 16:00, Sala Conferenze Centro De Giorgi
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