Sobajima, Motohiro; Wakasugi, Yuta Diffusion phenomena for the wave equation with space-dependent damping term growing at infinity. (English) Zbl 1391.35262 Adv. Differ. Equ. 23, No. 7-8, 581-614 (2018). Summary: In this paper, we study the asymptotic behavior of solutions to the wave equation with damping depending on the space variable and growing at the spatial infinity. We prove that the solution is approximated by that of the corresponding heat equation as time tends to infinity. The proof is based on semigroup estimates for the corresponding heat equation having a degenerate diffusion at spatial infinity and weighted energy estimates for the damped wave equation. To construct a suitable weight function for the energy estimates, we study a certain elliptic problem. Cited in 5 Documents MSC: 35L20 Initial-boundary value problems for second-order hyperbolic equations 35B40 Asymptotic behavior of solutions to PDEs 47B25 Linear symmetric and selfadjoint operators (unbounded) PDFBibTeX XMLCite \textit{M. Sobajima} and \textit{Y. Wakasugi}, Adv. Differ. Equ. 23, No. 7--8, 581--614 (2018; Zbl 1391.35262) Full Text: arXiv Euclid