Abstract:

In physics, noise is usually associated with small, fast perturbations to the system under study — something we want to eliminate. However, in complex systems such as turbulent flows and climate dynamics, noise should be considered the result of different dynamical processes that cannot be ignored. In this talk, I will review some basic notions about noise, providing examples where fast, small perturbations play a significant role in explaining rare, large-scale events. First, I will demonstrate how the concept of noise, when defined in relation to the specific physical problem being investigated, can offer a straightforward and clear-cut explanation of the observed physical phenomena. Next, I will discuss the effect of climate noise. After a brief overview of Hasselmann's pioneering work, I will discuss the mechanism of stochastic resonance and its relevance to climate change. Finally, I will present new experimental and theoretical results on stochastic resonance as applied to magnetic particles in turbulence.

Introduction of speaker:

Roberto Benzi is an emeritus professor of theoretical physics at the University of Rome "Tor Vergata". His work focuses primarily on statistical mechanics, dynamical systems, turbulence, computational fluid dynamics and population dynamics. In the 1980s, he introduced the concepts of stochastic resonance and multifractal theory of turbulence with Parisi and other collaborators. He also developed the Lattice Boltzmann Method with S. Succi. In the context of turbulence, he exploited the concept of extended self-similarity to obtain precise values of the anomalous exponents. More recently, he has generalised the Lattice Boltzmann method in order toinvestigate stable emulsions and the solid-liquid transition. Benzi is a member of the Academia Europaea. He has received several awards, including the IBM International Prize for Outstanding Technical and Scientific Innovation, the LF Richardson Medal from the European Geophysical Union, and the Ig Nobel Prize in Physics.

审核：刘有晟、游小清