Formulae for the derivatives of solutions of diffusion equations are derived which clearly exhibit, and allow estimation of, the equations' smoothing properties. These also give formulae for the logarithmic gradient of the corresponding heat kernels, extending and giving a very elementary proof of B
Heat Equation Derivative Formulas for Vector Bundles
β Scribed by Bruce K. Driver; Anton Thalmaier
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 411 KB
- Volume
- 183
- Category
- Article
- ISSN
- 0022-1236
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β¦ Synopsis
We use martingale methods to give Bismut type derivative formulas for differentials and co-differentials of heat semigroups on forms, and more generally for sections of vector bundles. The formulas are mainly in terms of Weitzenbo ck curvature terms; in most cases derivatives of the curvature are not involved. In particular, our results improve B. K. Driver's formula in (1997, J. Math. Pures Appl. (9) 76, 703 737) for logarithmic derivatives of the heat kernel measure on a Riemannian manifold. Our formulas also include the formulas of K. D.
π SIMILAR VOLUMES
AND Frank MERle Universite Cergy Pontoise and Universite Paris VI, 75230 Paris Cedex, France
We prove a Liouville theorem for the following heat system whose nonlinearity has no gradient structure: where pq > 1, p β₯ 1, q β₯ 1, and | p -q| small. We then deduce a localization property and uniform L β estimates of blowup solutions of this system.
## Abstract Heat transfer plays a major role in the processing of many particulate materials. The heat flux vector is commonly modelled by the Fourier's law of heat conduction and for complex materials such as nonβlinear fluids, porous media, or granular materials, the coefficient of thermal conduc