@article{ECP992,
author = {Anton Thalmaier},
title = {Some Remarks on the Heat Flow for Functions and Forms},
journal = {Electron. Commun. Probab.},
fjournal = {Electronic Communications in Probability},
volume = {3},
year = {1998},
keywords = {Heat semigroup, heat equation, Brownian motion, damped parallel translation, Ricci curvature.},
abstract = {This note is concerned with the differentiation of heat semigroups on Riemannian manifolds. In particular, the relation $dP_tf=P_tdf$ is investigated for the semigroup generated by the Laplacian with Dirichlet boundary conditions. By means of elementary martingale arguments it is shown that well-known properties which hold on complete Riemannian manifolds fail if the manifold is only BM-complete. In general, even if $M$ is flat and $f$ smooth of compact support, $\Vert dP_tf\Vert_\infty$ cannot be estimated on compact time intervals in terms of $f$ or $df$.},
pages = {no. 6, 43-49},
issn = {1083-589X},
doi = {10.1214/ECP.v3-992},
url = {http://ecp.ejpecp.org/article/view/992}}