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Construction of Green's functions for the Boltzmann equations. Shih-Hsien Yu Department of Mathematics National University of Singapore. Motivation to investigate Green’s function for Boltzmann equation before 2003. Nonlinear time-asymptotic stability of a Boltzmann shock profile
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Construction of Green's functions for the Boltzmann equations Shih-Hsien Yu Department of Mathematics National University of Singapore
Motivation to investigate Green’s function for Boltzmann equation before 2003 • Nonlinear time-asymptotic stability of a Boltzmann shock profile Zero total macroscopic perturbations • Nonlinear time-asymptotic stability of a Knudsen layer for the Boltzmann Equation Mach number <-1
Green’s function of linearized equation around a global Maxwellian, • Fourier transformation • The inverse transformation
Initial value problem • Particle-like wave-like decomposition
Pointwise of structure of the Green’s function • Space dimension=3 • Space dimension=1
Macroscopic wave structure of 1-D Green’s function Application: Pointwise time-asymptotic stability of a global Maxwellian state in 1-D.
Green’s function of linearized equation around a global Maxwellian M, , in a half-space problem x>0. Green identity: Boundary value estimates ( a priori estimate):
Approximate boundary data for case |Mach(M)|<1 Upwind damping approximation to the boundary data
Green’s function of linearized equation around a stationary shock profile .
Separation of wave structures Transversal wave Compressive wave
2. Hyperbolic Decomposition Transversal wave Compressive wave 3. Transverse Operator and Local Wave Front tracing
4. Coupling of T and D operators 5. Respond to Coupling
6. T-C scheme for An estimates
A Diagram for A Diagram for general pattern + extra time decaying rate in microscopic component nonlinear stability of Boltzmann shock profile
Applications of the Green’s functions • Nonlinear invariant manifolds for steady Boltzmann flow
Applications of the Green’s functions • Milne’s problme