文摘
In this paper, we derive energy estimates and \(L^1-L^1\) estimates, for the solution to the Cauchy problem for the doubly dissipative wave equation $$\begin{aligned} {\left\{ \begin{array}{ll} u_{tt}-\Delta u+u_t-\Delta u_t=0,&{}\quad t\ge 0,\ x\in {\mathbb {R}}^n,\\ (u,u_t)(0,x)=(u_0,u_1)(x). \end{array}\right. } \end{aligned}$$The solution is influenced both by the diffusion phenomenon created by the damping term \(u_t\), and by the smoothing effect brought by the damping term \(-\Delta u_t\). Thanks to these two effects, we are able to obtain linear estimates which may be effectively applied to find global solutions in any space dimension \(n\ge 1\), to the problems with power nonlinearities \(|u|^p\), \(|u_t|^p\) and \(|\nabla u|^p\), in the supercritical cases, by only assuming small data in the energy space, and with \(L^1\) regularity. We also derive optimal energy estimates and \(L^1-L^1\) estimates, for the solution to the semilinear problems.KeywordsDissipative wave equationCritical exponentGlobal small data solutionsPower nonlinearity\(L^1-L^1\) estimatesThe author is supported by INdAM - GNAMPA Project 2016 and is member of the Gruppo Nazionale per l’Analisi Matematica, la Probabilità e le loro Applicazioni (GNAMPA) of the Istituto Nazionale di Alta Matematica (INdAM).