normalized device coordinates (NDC)

It is proved that under the condition that normalized coordinates exist the system must be weakly linearly degenerate if the Cauchy problem for general quasilinear hyperbolic systems with characteristics with constant multiplicity with arbitrary small C 1 initial data always admits a unique global C 1 solution u=u(t,x) on t≥0.

对具常重特征的拟线性双曲组 ,在正规化坐标存在的假设下 ,证明了若其Chauchy问题对任意小C1初值总有整体C1解 ,则方程组必为弱线性退化 。