证明下列非线性波动方程的Cauchy问题v_(tt)-α△v_(tt)-Δv=g(v)-αΔg(v),x∈R~N,t〉0,(1)v(x,0)=v_0(x),v_t(x,0)=v_1(x),x∈R~N(2)在空间C~2([0,∞);H~s(R~N))(s〉N/2)中存在唯一整体广义解v和在空间C~2([0,∞);H~s(R~N))(s〉2+N/2N)中存在唯一整体古典解v,即u∈C~2([0,∞);C_B~2(R~N)).还证明Cauchy问题(1),(2)在C~3([0,∞);W~(m,p)(R~N)∩L~∞(R~N))(m≥0,1≤p≤∞)中有唯一整体广义解v和在C~3([0,∞);W~(m,p)(R~N)∩L~∞(R~N))(m〉2+N/P)中有唯一整体古典解v,即v∈C~3([0,∞);C~2(R~N)∩L~∞(R~N)).
We prove that the Cauchy problem for the nonlinear wave equationvtt -αΔvtt -Δv = g(v) -αΔg(v),x∈RN,t〉0,(1)v(x,0)=v0(x),vt(x,0) = v1(x),x∈RN(2)has a unique global generalized solution v in C2([0,∞);Hs(RN))(s〉N/2) and a uniqueglobal classical solution v in C2([0,∞);Hs(RN))(s〉2+N/2),i.e.,v∈C2([0,∞);CB2(Rn)).We also prove that the Cauchy problem(1),(2) admits a unique global generalizedsolution v in C3([0,∞);Wm,p(RN)∩L∞(RN))(m≥0,1≤p≤∞) and a uniqueglobal classical solution v in C3{[0,∞);Wm,p(RN) D L∞(RN))(m〉2 + N/P),i.e.,v∈C3([0,∞);C2(RN)∩L∞(RN)).