1. Department of Mathematics, Xiamen University, Xiamen 361005, P. R. China;
2. Department of Applied Mathematics, Tsinghua University, Beijing 100084, P. R. China
Abstract:
For the nonlinear wave equation in
, in 1980 Kato proved the solution of Cauchy problem may blow up in finite time
. In the present work his result allowing
is improved by using different estimates
Foundation item: the National Natural Science Foundation of China (19771069)