Hitting probabilities and potential theory for the brownian path-valued process
Gall, Jean-François Le
Annales de l'Institut Fourier, Tome 44 (1994), p. 277-306 / Harvested from Numdam

Nous considérons le “mouvement brownien à valeurs trajectoires” déjà étudié dans [LG1], et dans [LG2], qui est étroitement lié au super mouvement brownien. Nous obtenons plusieurs résultats de théorie du potentiel probabiliste relatifs à ce processus. En particulier, nous donnons une description explicite des mesures capacitaires de certains sous-ensembles de l’espace des trajectoires, tels que l’ensemble des trajectoires qui rencontrent un sous-ensemble fermé fixé de d . Ces mesures d’équilibre, qui sont les lois des solutions de certaines équations différentielles stochastiques, sont associées à des problèmes variationnels dans l’ensemble des mesures de probabilité sur l’espace des trajectoires. Nous nous intéressons aussi à des classes particulières d’ensembles polaires pour le mouvement brownien à valeurs trajectoires. Ces derniers résultats sont très liés aux questions de polarité pour le super mouvement brownien étudiées récemment par Dynkin et d’autres auteurs, ainsi qu’aux problèmes d’éliminabilité de singularités pour l’équation aux dérivées partielles non linéaire Δu=u 2 .

We consider the Brownian path-valued process studied in [LG1], [LG2], which is closely related to super Brownian motion. We obtain several potential-theoretic results related to this process. In particular, we give an explicit description of the capacitary distribution of certain subsets of the path space, such as the set of paths that hit a given closed set. These capacitary distributions are characterized as the laws of solutions of certain stochastic differential equations. They solve variational problems in the space of probability measures on the path space. We also investigate some special classes of polar sets for the path-values process. These results are closely related to the polarity questions for super Brownian motion recently investigated by Dynkin and others. They are also related to removable singularities for the nonlinear partial differential equation Δu=u 2 .

@article{AIF_1994__44_1_277_0,
     author = {Gall, Jean-Fran\c cois Le},
     title = {Hitting probabilities and potential theory for the brownian path-valued process},
     journal = {Annales de l'Institut Fourier},
     volume = {44},
     year = {1994},
     pages = {277-306},
     doi = {10.5802/aif.1398},
     mrnumber = {94m:60155},
     zbl = {0794.60077},
     language = {en},
     url = {http://dml.mathdoc.fr/item/AIF_1994__44_1_277_0}
}
Gall, Jean-François Le. Hitting probabilities and potential theory for the brownian path-valued process. Annales de l'Institut Fourier, Tome 44 (1994) pp. 277-306. doi : 10.5802/aif.1398. http://gdmltest.u-ga.fr/item/AIF_1994__44_1_277_0/

[AL]R. Abraham, J.F. Le Gall, La mesure de sortie du super mouvement brownien, Probab. Th. Rel. Fields, to appear. | Zbl 0801.60040

[AP]D.R. Adams, J.C. Polking, The equivalence of two definitions of capacity, Proc. Amer. Math. Soc., 37 (1973), 529-534. | MR 48 #6451 | Zbl 0251.31005

[BP]P. Baras, M. Pierre, Singularités éliminables pour des équations semi-linéaires, Ann. Inst. Fourier, 34-1 (1984), 185-206 | Numdam | MR 86j:35063 | Zbl 0519.35002

[DM]C. Dellacherie, P.A. Meyer, Probabilités et Potentiel, Chapitres I à IV, Hermann, 1975. | MR 58 #7757 | Zbl 0323.60039

[Do]J.L. Doob, Classical Potential Theory and its Probabilistic Counterpart, Springer, 1984. | MR 85k:31001 | Zbl 0549.31001

[Dy1]E.B. Dynkin, Green's and Dirichlet spaces associated with fine Markov processes, J. Funct. Anal., 47 (1982), 381-418. | MR 83m:60097 | Zbl 0488.60083

[Dy2]E.B. Dynkin, A probabilistic approach to one class of nonlinear differential equations, Probab. Th. Rel. Fields, 89 (1991), 89-115. | MR 92d:35090 | Zbl 0722.60062

[Dy3]E.B. Dynkin, Superprocesses and parabolic nonlinear differential equations, Ann. Probab., 20 (1992), 942-962. | MR 93d:60124 | Zbl 0756.60074

[FG]P.J. Fitzsimmons, R.K. Getoor, On the potential theory of symmetric Markov processes, Math. Ann., 281 (1988), 495-512. | MR 89k:60110 | Zbl 0627.60067

[GV]A. Gmira, L. Véron, Boundary singularities of some nonlinear elliptic equations, Duke Math. J., 64 (1991), 271-324. | MR 93a:35053 | Zbl 0766.35015

[HW]R.A. Hunt, R.L. Wheeden, Positive harmonic functions in Lipschitz domains, Trans. Amer. Math. Soc., 147 (1970), 507-527. | MR 43 #547 | Zbl 0193.39601

[LG1]J.F. Le Gall, A class of path-valued Markov processes and its applications to superprocesses, Probab. Th. Rel. Fields, 95 (1993), 25-46. | MR 94f:60093 | Zbl 0794.60076

[LG2]J.F. Le Gall, A path-valued Markov process and its connections with partial differential equations, Proceedings of the First European Congress of Mathematics, to appear. | Zbl 0812.60058

[Me]N.G. Meyers, A theory of capacities for potentials of functions in Lebesgue classes, Math. Scand., 26 (1970), 255-292. | MR 43 #3474 | Zbl 0242.31006

[Pe]E.A. Perkins, Polar sets and multiple points for super Brownian motion, Ann. Probab., 18 (1990), 453-491. | MR 91i:60109 | Zbl 0721.60046

[Sh]Y.C. Sheu, A characterization of polar sets on the boundary, preprint (1993)