On écrit une formule de Bismut intrinsèque pour la hessienne d'un semigroupe de la chaleur ou d'une fonction harmonique sur une variété, en calculant des dérivées secondes directionnelles de familles de martingales, et en filtrant ensuite le bruit superflu. Cela nous permet d'obtenir des estimées de la hessienne dans un cadre très général. Avec des hypothèses de symétrie radiale de la variété, on améliore encore ces estimées.
We obtain an intrinsic version of a Bismut type formula for the Hessian of heat semigroups, resp. harmonic functions, by computing second order directional derivatives of families of martingales, along with filtering of redundant noise. As applications we provide a Hessian estimate in the general case as well as a slightly improved one in the radially symmetric situation.
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@article{CRMATH_2003__336_8_661_0, author = {Arnaudon, Marc and Plank, Holger and Thalmaier, Anton}, title = {A {Bismut} type formula for the {Hessian} of heat semigroups}, journal = {Comptes Rendus. Math\'ematique}, pages = {661--666}, publisher = {Elsevier}, volume = {336}, number = {8}, year = {2003}, doi = {10.1016/S1631-073X(03)00123-7}, language = {en}, url = {http://archive.numdam.org/articles/10.1016/S1631-073X(03)00123-7/} }
TY - JOUR AU - Arnaudon, Marc AU - Plank, Holger AU - Thalmaier, Anton TI - A Bismut type formula for the Hessian of heat semigroups JO - Comptes Rendus. Mathématique PY - 2003 SP - 661 EP - 666 VL - 336 IS - 8 PB - Elsevier UR - http://archive.numdam.org/articles/10.1016/S1631-073X(03)00123-7/ DO - 10.1016/S1631-073X(03)00123-7 LA - en ID - CRMATH_2003__336_8_661_0 ER -
%0 Journal Article %A Arnaudon, Marc %A Plank, Holger %A Thalmaier, Anton %T A Bismut type formula for the Hessian of heat semigroups %J Comptes Rendus. Mathématique %D 2003 %P 661-666 %V 336 %N 8 %I Elsevier %U http://archive.numdam.org/articles/10.1016/S1631-073X(03)00123-7/ %R 10.1016/S1631-073X(03)00123-7 %G en %F CRMATH_2003__336_8_661_0
Arnaudon, Marc; Plank, Holger; Thalmaier, Anton. A Bismut type formula for the Hessian of heat semigroups. Comptes Rendus. Mathématique, Tome 336 (2003) no. 8, pp. 661-666. doi : 10.1016/S1631-073X(03)00123-7. http://archive.numdam.org/articles/10.1016/S1631-073X(03)00123-7/
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