Information flows, turbulence, and predictability within the cosmic web
Invited Talk: Mark Neyrinck
I plan to discuss the high degree of chaos within many-stream regions of the Universe, i.e. the cosmic web. Especially within galaxies, the detailed structure may be unpredictable, not just in practice but in principle. Two reasons lead us to think so: first, phenomena such as AGN can broadcast very small-scale fluctuations to galaxy scale; second, recent findings about “spontaneous stochasticity” in turbulent systems. The chaos is more extreme than usually appreciated: the “real” butterfly effect is just as strong for a microscopic butterfly. Quoting a 2024 PRL title, “spontaneous stochasticity amplifies even thermal noise to the largest scales of turbulence in a few eddy turnover times”. In contrast, information seems to be remarkably preserved and in single-stream, void regions; these seem to be totally predictable. If time and progress permit, I will also talk about some of my recent work about how quantitatively analogous river systems, city networks, and the cosmic web are.
Event Timeslots (1)
Friday
-