In this paper, we show that the solution to the semilinear wave equation with a potential of quadratic type blows up in finite time. We also give an upper bound estimate for the lifespan of the solution.
"Remarks on the lifespan ofsolutions to wave equationswith a potential." Rocky Mountain J. Math. 47 (5) 1743 - 1748, 2017. https://doi.org/10.1216/RMJ-2017-47-5-1743