Electronic Journal of Differential Equations, Vol. 2024 (2024), No. 04, pp. 1-31. Title: Global existence and asymptotic profile for a damped wave equation with variable-coefficient diffusion Authors: Yuequn Li (Nanjing Normal Univ., Nanjing, China) Hui Liu (Nanjing Normal Univ., Nanjing, China Fei Guo (Nanjing Normal Univ., Nanjing, China) Abstract: We considered a Cauchy problem of a one-dimensional semilinear wave equation with variable-coefficient diffusion, time-dependent damping, and perturbations. The global well-posedness and the asymptotic profile are given by employing scaling variables and the energy method. The lower bound estimate of the lifespan to the solution is obtained as a byproduct. Submitted August 27, 2023. Published January 08, 2024. Math Subject Classifications: 35B44, 35G25. Key Words: Semilinear damped wave equation; asymptotic profile; lifespan; scaling variables; energy method.