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On some energy inequalities and supnorm estimates for advection-diffusion equations in \(\mathbb R^n\). (English) Zbl 1284.35091

Summary: We show how some suitable standard energy inequalities can be used for a simple short derivation of the fundamental supnorm estimate \[ ||u(\cdot, t)||_{L^\infty (\mathbb R^n)}\leq K(n,p)||u(\cdot, 0)||_{L^p(\mathbb R^n)}t^{-\frac{n}{2_p}} \;\forall t>0 \] for solutions of advection-diffusion equations of the form \(u_t+\mathrm{div}\;\mathbf f(u)={\varDelta}u\) (and some generalizations) in the whole space \(\mathbb R^n\), where \(n\geq 1\) is arbitrary. Our approach can be used for other parabolic equations as well, including degenerate cases like porous medium type equations and \(p\)-Laplacian evolution equations. Some open problems and related results of interest are also given.

MSC:

35B45 A priori estimates in context of PDEs
35K58 Semilinear parabolic equations
35K15 Initial value problems for second-order parabolic equations
Full Text: DOI

References:

[1] Kreiss, H. O.; Lorenz, J., Initial-Boundary Value Problems and the Navier-Stokes Equations (1989), Academic Press: Academic Press Boston · Zbl 0689.35001
[2] Oleinik, O. A.; Kruzhkov, S. N., Quasilinear second order parabolic equations with many independent variables, Russian Math. Surveys, 16, 105-146 (1961) · Zbl 0112.32604
[3] Serre, D., Systems of Conservation Laws, Vol. I (1999), Cambridge University Press: Cambridge University Press Cambridge · Zbl 0930.35001
[4] Cipriani, F.; Grillo, G., Uniform bounds for solutions to quasilinear parabolic equations, J. Differential Equations, 177, 209-234 (2001) · Zbl 1036.35043
[5] Escobedo, M.; Zuazua, E., Large time behavior for convection-diffusion equations in \(R^N\), J. Funct. Anal., 100, 119-161 (1991) · Zbl 0762.35011
[6] Porzio, M. M., On decay estimates, J. Evol. Equ., 9, 561-591 (2009) · Zbl 1239.35023
[7] Schonbek, M. E., Uniform decay rates for parabolic conservation laws, Nonlinear Anal. TMA, 10, 943-956 (1986) · Zbl 0617.35060
[8] Zingano, P. R., Nonlinear \(L^2\) stability under large disturbances, J. Comput. Appl. Math., 103, 207-219 (1999) · Zbl 0942.35027
[9] Nash, J., Continuity of solutions of parabolic and elliptic equations, Amer. J. Math., 80, 931-954 (1958) · Zbl 0096.06902
[10] Hörmander, L., Lectures on Nonlinear Hyperbolic Differential Equations (1997), Springer: Springer Berlin · Zbl 0881.35001
[11] Escobedo, M.; Vazquez, J. L.; Zuazua, E., Asymptotic behaviour and source-type solutions for a diffusion-convection equation, Arch. Ration. Mech. Anal., 124, 43-65 (1993) · Zbl 0807.35059
[12] Carlen, E. A.; Loss, M., Sharp constant in Nash’s inequality, Int. Math. Res. Not. IMRN, 213-215 (1993) · Zbl 0822.35018
[13] Beckner, W., Geometric proof of Nash’s inequality, Int. Math. Res. Not. IMRN, 67-71 (1998) · Zbl 0895.35015
[14] Braz e. Silva, P.; Schütz, L.; Zingano, P. R., Decay estimates for solutions of quasilinear parabolic equations in heterogeneous media, Adv. Differ. Equ. Control Process., 6, 101-112 (2010) · Zbl 1219.35025
[15] Evans, L. C., Partial Differential Equations (1998), Amer. Math. Society: Amer. Math. Society Providence · Zbl 0902.35002
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