Blow-Up of Solutions for the Coupled System of Tricomi Equations with Derivative Nonlinearity
The small initial values problem of coupled Tricomi equations with derivative nonlinearity with space dimensional n≥2 is studied.By defining the energy solutions of the problem and constructing the adequate test function,the integral functional inequalities of solutions are obtained.According to the range of nonlinearities exponents,the research process is divided into the sub-critical case and critical cases.By using the improved Kato's lemma in the sub-critical case and iterative method in the critical case,it shows that solutions to the problem blow up in finite time.Meanwhile,the upper bound lifespan estimates in power form for the sub-critical case and exponential form for the critical case are obtained,which general-izes the conclusions of existing literatures.