Host: Prof. Jianda Wu

Venue: TDLI Meeting Room N601

Tencent meeting link: https://meeting.tencent.com/dm/7nuJiwRpTrXB     Meeting ID: 323375004, no password

Abstract:

Fluid turbulence happens at scales ranging from a water tub and a geographical storm to the size of a galaxy. Although the underlying hydrodynamic equation, i.e., the Navier-Stokes equation, has been known for over a century, many fundamental questions on turbulence remain unresolved. In the fully developed homogeneous turbulence, there is a scale range called the inertial range, in which the statistically stationary turbulence forms a self-similar steady flow. Two-dimensional, fully developed turbulence may possess the largest possible symmetry, the conformal symmetry. We  propose a conformal field theory in the classical limit c→−∞ for the direct enstrophy cascade and a c = 0 boundary logarithmic conformal field theory for the inverse energy cascade.   We show that the proposed theory gives rise to the right energy spectrum E(k):  Kraichnan-Batchelor scaling E(k)~k^−3 for the direct enstrophy cascade and Kolmogorov-Kraichnan scaling E(k) ~ k^-5/3 for the inverse energy cascade. 

Biography:

Xiaoquan Yu is an assistant professor at Graduate School of China Academy of Engineering Physics (GSCAEP). He obtained his PhD in theoretical physics in 2012 from SISSA.  From 2013-2015 he conducted postdoctoral research at New Zealand institute for advanced study. He started to work at the physics department of the University of Otago as a research fellow in 2015. In 2019 he joined GSCAEP. His research focuses on quantum fluids, domain wall and vortex dynamics, turbulence and disordered  quantum systems.