Pour une classe de processus de diffusion de rang deux, i.e. lorsque seuls des crochets de Poisson d'ordre un permettent d'engendrer l'espace, nous obtenons une représentation parametrix de type McMean-Singer [J. Differential Geom. 1 (1967) 43-69] de la densité. Nous en dérivons une borne supérieure gaussienne explicite et une borne inférieure partielle qui caractérisent la singularité additionnelle induite par la dégénérescence. Nous donnons ensuite un théorème limite local pour une approximation par chaîne de Markov associée. Le point crucial est que la faible dégénérescence permet d'exploiter les techniques initialement introduites par Konakov et Molchanov [Teor. Veroyatn. Mat. Statist. 31 (1984) 51-64] puis développées dans [Probab. Theory Related Fields 117 (2000) 551-587] et qui reposent sur des approximations gaussiennes.
For a class of degenerate diffusion processes of rank 2, i.e. when only Poisson brackets of order one are needed to span the whole space, we obtain a parametrix representation of McKean-Singer [J. Differential Geom. 1 (1967) 43-69] type for the density. We therefrom derive an explicit gaussian upper bound and a partial lower bound that characterize the additional singularity induced by the degeneracy. This particular representation then allows to give a local limit theorem with the usual convergence rate for an associated Markov chain approximation. The key point is that the “weak” degeneracy allows to exploit the techniques first introduced in Konakov and Molchanov [Teor. Veroyatn. Mat. Statist. 31 (1984) 51-64] and then developed in [Probab. Theory Related Fields 117 (2000) 551-587] that rely on gaussian approximations.
Mots clés : degenerate diffusion processes, parametrix, Markov chain approximation, local limit theorems
@article{AIHPB_2010__46_4_908_0, author = {Konakov, Valentin and Menozzi, St\'ephane and Molchanov, Stanislav}, title = {Explicit parametrix and local limit theorems for some degenerate diffusion processes}, journal = {Annales de l'I.H.P. Probabilit\'es et statistiques}, pages = {908--923}, publisher = {Gauthier-Villars}, volume = {46}, number = {4}, year = {2010}, doi = {10.1214/09-AIHP207}, mrnumber = {2744877}, zbl = {1211.60036}, language = {en}, url = {http://www.numdam.org/articles/10.1214/09-AIHP207/} }
TY - JOUR AU - Konakov, Valentin AU - Menozzi, Stéphane AU - Molchanov, Stanislav TI - Explicit parametrix and local limit theorems for some degenerate diffusion processes JO - Annales de l'I.H.P. Probabilités et statistiques PY - 2010 SP - 908 EP - 923 VL - 46 IS - 4 PB - Gauthier-Villars UR - http://www.numdam.org/articles/10.1214/09-AIHP207/ DO - 10.1214/09-AIHP207 LA - en ID - AIHPB_2010__46_4_908_0 ER -
%0 Journal Article %A Konakov, Valentin %A Menozzi, Stéphane %A Molchanov, Stanislav %T Explicit parametrix and local limit theorems for some degenerate diffusion processes %J Annales de l'I.H.P. Probabilités et statistiques %D 2010 %P 908-923 %V 46 %N 4 %I Gauthier-Villars %U http://www.numdam.org/articles/10.1214/09-AIHP207/ %R 10.1214/09-AIHP207 %G en %F AIHPB_2010__46_4_908_0
Konakov, Valentin; Menozzi, Stéphane; Molchanov, Stanislav. Explicit parametrix and local limit theorems for some degenerate diffusion processes. Annales de l'I.H.P. Probabilités et statistiques, Tome 46 (2010) no. 4, pp. 908-923. doi : 10.1214/09-AIHP207. http://www.numdam.org/articles/10.1214/09-AIHP207/
[1] Bounds for the fundamental solution of a parabolic equation. Bull. Amer. Math. Soc. 73 (1967) 890-896. | MR | Zbl
.[2] Premières majorations de la densité d'une diffusion sur Rm, méthode de la parametrix. Astérisques 84-85 (1978) 43-53. | Zbl
.[3] Développement asymptotique du noyau de la chaleur hypoelliptique hors du cut-locus. Ann. Sci. École Norm. Sup. (4) 21 (1988) 307-331. | Numdam | MR | Zbl
.[4] Décroissance exponentielle du noyau de la chaleur sur la diagonale, II. Probab. Theory Related Fields 90 (1991) 377-402. | MR | Zbl
and .[5] Some results on partial differential equations and asian options. Math. Models Methods Appl. Sci. 3 (2001) 475-497. | MR | Zbl
, and .[6] Normal Approximations and Asymptotic Expansions. Wiley, New York, 1976. | MR | Zbl
and .[7] The law of the Euler scheme for stochastic differential equations, II. Convergence rate of the density. Monte Carlo Methods Appl. 2 (1996) 93-128. | MR | Zbl
and .[8] Calcul stochastique et opérateurs dégénérés du second ordre, I. Résolvantes, théorème de Hörmander et applications. Bull. Sci. Math. 114 (1990) 421-462. | MR | Zbl
.[9] Calcul stochastique et opérateurs dégénérés du second ordre, II. Problème de Dirichlet. Bull. Sci. Math. 115 (1991) 81-122. | MR | Zbl
.[10] Markov Processes. Springer, Berlin, 1963. | Zbl
.[11] Partial Differential Equations of Parabolic Type. Prentice-Hall, Englewood Cliffs, 1964. | MR | Zbl
.[12] Isotropic hypoellipticity and trend to equilibrium for the Fokker-Planck equation with a high-degree potential. Arch. Ration. Mech. Anal. 171 (2004) 151-218. | MR | Zbl
and .[13] Hypoelliptic second order differential operators. Acta. Math. 119 (1967) 147-171. | MR | Zbl
. and S. A Molchanov. On the convergence of Markov chains to diffusion processes. Teor. Veroyatn. Mat. Statist. (in Russian) 31 (1984) 51-64. English translation in Theory Probab. Math. Statist. 31 (1985) 59-73. |[15] Local limit theorems for transition densities of Markov chains converging to diffusions. Probab. Theory Related Fields 117 (2000) 551-587. | MR | Zbl
and .[16] Explicit parametrix and local limit theorems for some degenerate diffusion processes, 2009. Available at http://hal.archives-ouvertes.fr/hal-00256588/fr/. | Numdam | MR | Zbl
, and .[17] Zufällige Bewegungen (zur Theorie der Brownschen Bewegung). Ann. of Math. (2) 35 (1934) 116-117. | MR | Zbl
. and D Stroock. Applications of the Malliavin calculus, III. J. Fac. Sci. Univ. Tokyo Sect. IA Math. 34 (1987) 391-442. |[19] Curvature and the eigenvalues of the Laplacian. J. Differential Geom. 1 (1967) 43-69. | MR | Zbl
and .[20] Geometric ergodicity of some hypo-elliptic diffusions for particle motions. Inhomogeneous random systems. Markov Process. Related Fields 8 (2004) 199-214. | MR | Zbl
and .[21] Applications of the stationary phase method in limit theorems for Markov chains. Dokl. Akad. Nauk SSSR (Translated in Soviet Math. Dokl. (18) 265-269) 233 (1977) 11-14. | MR | Zbl
and .[22] Simplified Malliavin calculus. Séminaire de Probabilités, XX 101-130. Springer, Berlin, 1986. | Numdam | MR | Zbl
.[23] Malliavin Calculus and Related Topics. Springer, New York, 1995. | MR | Zbl
.[24] Diffusion semigroups corresponding to uniformly elliptic divergence form operators. Séminaire de Probabilités, XXII 316-347. Springer, Berlin, 1988. | Numdam | MR | Zbl
.[25] Stochastic Hamiltonian systems: Exponential convergence to the invariant measure, and discretization by the implicit Euler scheme. Markov Process. Related Fields 8 (2002) 163-198. | MR | Zbl
.[26] Competitive Monte Carlo methods for the pricing of Asian Options. Journal of Computational Finance 5 (2001) 39-59.
and .[27] Estimates for the characteristic functions of certain degenerate multidimensional distributions. Teor. Verojatn. Primen. (Translated in Theory Probab. Appl. 22 101-113) 17 (1972) 99-110. | MR | Zbl
.Cité par Sources :