A note on weakly hyperbolic equations with analytic principal part

Claudia Garetto, Michael Ruzhansky
2014 Journal of Mathematical Analysis and Applications  
In this paper we show how to include low order terms in the $C^{\infty}$ well-posedness results for weakly hyperbolic equations with analytic time-dependent coefficients. This is achieved by doing a different reduction to a system from the previously used one. We find the Levi conditions such that the $C^{\infty}$ well-posedness continues to hold.
doi:10.1016/j.jmaa.2013.09.011 fatcat:sovypend65dhtltntla47wbmse