6533b7defe1ef96bd127696c

RESEARCH PRODUCT

A logarithmic fourth-order parabolic equation and related logarithmic Sobolev inequalities

Jean DolbeaultAnsgar JüngelIvan Gentil

subject

Cauchy problemLogarithmApplied MathematicsGeneral Mathematics35B40Mathematical analysisNon-equilibrium thermodynamicsPoincaré inequalitySobolev inequalityNonlinear systemsymbols.namesake35K3535K55symbolsPeriodic boundary conditionsUniquenessMathematics

description

A logarithmic fourth-order parabolic equation in one space dimension with periodic boundary conditions is studied. This equation arises in the context of fluctuations of a stationary nonequilibrium interface and in the modeling of quantum semiconductor devices. The existence of global-in-time non-negative weak solutions and some regularity results are shown. Furthermore, we prove that the solution converges exponentially fast to its mean value in the ``entropy norm'' and in the Fisher information, using a new optimal logarithmic Sobolev inequality for higher derivatives. In particular, the rate is independent of the solution and the constant depends only on the initial value of the entropy.

https://doi.org/10.4310/cms.2006.v4.n2.a1