Critical extinction exponents for polytropic filtration equations with nonlocal source and absorption

In this article, by applying the super-solution and sub-solution methods, instead of energy estimate methods, the authors investigate the critical extinction exponents for a polytropic filtration equation with a nonlocal source and an absorption term, and give a classification of the exponents and coefficients for the solutions to vanish in finite time or not, which improve one of our results (Applicable Analysis, 92(2013), 636–650) and the results of Zheng et al (Math. Meth. Appl. Sci., 36(2013), 730–743).