Display Abstract
 Title Decay estimates for unbounded solutions
 Name Maria Michaela M Porzio Country Italy Email porzio@mat.uniroma1.it Co-Author(s) Submit Time 2014-02-27 05:03:56 Session Special Session 37: Global or/and blowup solutions for nonlinear evolution equations and their applications
 Contents It is well known that the solution of the heat equation with summable initial datum $u_0$ becomes "immediately bounded" and satisfies the decay estimate $$\label{eqca} \| u(\cdot,t)\|_{L^\infty} \leq C \frac{\|u_0\|_{L^{1}}}{t^{\frac{N}{2}}}, \quad t> 0.$$ This "strong regularizing effect" is not a peculiarity of the heat equation since it appears also for a lot of other parabolic problems, also nonlinear, degenerate or singular like the p-Laplacian equation, the porous medium equation, the fast diffusion equation, etc. In a recent paper we have proved that this phenomenon occurs when the solutions satisfy certain integral inequalities. We investigate here what happens when this regularizing effect does not appear and which is the solutions' behavior in this case.