Qualitative properties of solutions to a generalized Fisher-KPP equation

Abstract: The following Fisher-KPP type equation $$u_t=Ku_{xx}-Bu^{q+Au^p,} \quad (x,t)\in\real\times(0,\infty),$$ with $p>q>0$ and $A$, $B$, $K$ positive coefficients, is considered. For both $p>q>1$ and $p>1$, $q=1$, we construct stationary solutions, establish their behavior as $|x|\to\infty$ and prove that they are separatrices between solutions decreasing to zero in infinite time and solutions presenting blow-up in finite time. We also establish decay rates for the solutions that decay to zero as $t\to\infty$.