2021-09-28T07:14:42Zhttps://tsukuba.repo.nii.ac.jp/oaioai:tsukuba.repo.nii.ac.jp:000186902021-03-01T19:14:20ZOn the 2 by 2 weakly hyperbolic systems木下, 保Ancona, Piero D'Kinoshita, TamotuSpagnolo, SergioWe study the wellposedness in the Gevrey classes $\gamma^{s}$ and in $C^{\infty}$ of the Cauchy problem for 2 by 2 weakly hyperbolic systems. In this paper we shall give some conditions to the case that the characteristic roots oscillate rapidly and vanish at an infinite number of points.journal articleDept. of Mathematics, Osaka UniversityDept. of Mathematics, Osaka City University2008-12application/pdfOsaka journal of mathematics445921939http://hdl.handle.net/2241/1044240030-6126AA00765910https://tsukuba.repo.nii.ac.jp/record/18690/files/OJM_45-4.pdfengDept. of Mathematics, Osaka UniversityDept. of Mathematics, Osaka City University