NCTS(South)/ NCKU Math Colloquium | |
DATE | 2013-04-18 16:10-17:00 |
PLACE | R204, 2F, NCTS, NCKU |
SPEAKER | 吳恭儉 博士 (Dr. Kung-Chien Wu)(英國 劍橋大學 純粹數學與數理統計系 (Dept. of Pure Math. and Math. Stat., Univ. of Cambridge, UK) ) |
TITLE | Wave Structures of the Linearized Boltzmann Equation in a Periodic Box |
ABSTRACT |
We study the wave structures of the linearized Boltzmann equation in a periodic box for non-smooth initial perturbations. The result reveals both the fluid and kinetic aspects of this model. The fluid-like waves are constructed as part of the long-wave expansion in the spectrum of the Fourier mode for the space variable, and the time decay rate of the fluid-like waves depends on the size of the domain. We design a Picard-type iteration for constructing the increasingly regular kinetic-like waves, which are carried by the transport equations and have exponential time decay rate. The iterated averaging lemma plays an important role in constructing the kinetic-like waves. We also supply some new ideas of this lemma. |