2025/01/29 by Hou, Fei, Yin, Huicheng, Yuan, Meng
#Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.2501.18646
In the paper [H. Kubo, Global existence for exterior problems of semilinear wave equations with the null condition in 2D, Evol. Equ. Control Theory 2 (2013), no. 2, 319-335], for the 2-D semilinear wave equation system (∂t2-Δ)vI=QI(∂tv, ∇xv) (1≤ I≤ M) in the exterior domain with Dirichlet boundary condition, it is shown that the small data smooth solution v=(v1, ⋅⋅⋅, vM) exists globally when the cubic nonlinearities QI(∂tv, ∇xv)=O(|∂tv|3+|∇xv|3) satisfy the null condition. We now focus on the global Dirichelt boundary value problem of 2-D wave maps equation with the form \Box uI=∑J,K,L=1MCIJKLuJQ0(uK,uL) (1≤ I≤ M) and Q0(f,g)=∂tf∂tg-∑j=12∂jf∂jg in exterior domain. By establishing some crucial classes of pointwise spacetime decay estimates for the small data solution u=(u1, ⋅⋅⋅, uM) and its derivatives, the global existence of u is shown.