The University of Wisconsin-Milwaukee, 2017 Under the Supervision of Professor Hans Volkmer The Fourier transform, F, on R N (N ≥ 1) transforms the Cauchy problem for the strongly damped wave equation u tt − ∆u t − ∆u = 0 to an ordinary differential equation in time t.We let u(t, x) be the solution of the problem given by the Fourier transform, and ν(t, ξ) be the asymptotic profile of F(u)(t, ξ) =û(t, ξ) found by Ikehata in [4].In this thesis we study the asymptotic expansions of the squared L 2 -norms of u(t, x), u(t, ξ) − ν(t, ξ), and ν(t, ξ) as t → ∞. With suitable initial data u(0, x) and u t (0, x), we establish the rate of growth or decay of the squared L 2 -norms of u(t, x) and ν(t, ξ) as t → ∞.By noting the cancellation of leading terms of their respective expansions, we conclude that the rate of convergence betweenû(t, ξ) and ν(t, ξ) in the L 2 -norm occurs quickly relative to their individual behaviors. Finally we consider three examples in order to illustrate the results.ii
Conclusion 129Bibliography 132 Appendix: Computing B m,n ,B m,n , and C m,n with Mathematica 134Curriculum Vitae 136