We introduce a direct method to analyze the blow-up of solutions to systems of ordinary differential inequalities, and apply it to study the blow-up of solutions to a weakly coupled system of semilinear heat equations. In particular, we give upper and lower estimates of the lifespan of the solution in the subcritical case.
"Lifespan of Solutions for a Weakly Coupled System of Semilinear Heat Equations." Tokyo J. Math. 43 (1) 163 - 180, June 2020. https://doi.org/10.3836/tjm/1502179300