Colloquium


DATE2019-05-30 16:10-17:00

PLACE數學館3174教室

SPEAKER洪盟凱 教授(中央大學數學系

TITLEComposite Hyperbolic Waves in Hyperbolic Resonant Systems of Balance Laws

ABSTRACT The global in time existence and behavior of composite hyperbolic waves to the resonant hyperbolic systems of balance laws are studied. The resonant hyperbolic systems we study have the property that all the eigenvalues of Jacobian matrix of the flux are coincided in the whole phase domain. We give an example of a weak solution with vacuum for the classical Riemann problem of some entirely resonant system to indicate that the self-similar Riemann solution is not an appropriate building block of Glimm scheme to Cauchy problem of such systems. Instead, we invent a regularized Riemann problem with perturbed Riemann data. The weak solutions of such Riemann problem consists of constant states separated by the composite hyperbolic waves, which are the combination of nonlinear hyperbolic waves and contact discontinuities. Such composite waves have finite total variations so that the generalized Glimm scheme can be applied to establish the global existence of weak solutions for the entirely resonant systems. The results indicate that the resonance provides a mechanism of amplifying the effect of singularity of Riemann data. It means that the generalized Riemann solutions with composite hyperbolic waves can be a more appropriate building block of generalized Glimm scheme for hyperbolic resonant system. This is a joint work with Hsin-Yi Lee (NCU), Jia-Chieh Chu (NTHU) and Shi-Wei Chou (Soochow University).