Huang, Yong Zhong et Wang, Meng Cheng, Analyticity of the sine family with L p-maximal regularity for second order Cauchy problems, Acta mathematica Sinica. English series (Print) , 26(3), 2010, pp. 561-568
If the second order problem ü(t)+B u.(t)+Au(t) = f(t), u(0) = u.(0) = 0 has L p-maximal regularity, 1 < p < ., the analyticity of the corresponding propagator of the sine type is shown by obtaining the estimates of . .(. 2 + .B + A).1. and .B(. 2 + .B + A).1. for . . C with Re. > ., where the constant . . 0.