Abstract
We consider a rough differential equation of the form dYt = ∑ iVi(Yt)dXti + V0(Yt)dt, where Xt is a Markovian rough path. We demonstrate that if the vector fields (Vi)0≤i≤d satisfy the parabolic Hörmander’s condition, then Yt admits a smooth density with a Gaussian type upper bound, given that the generator of Xt satisfy certain non-degenerate conditions. The main new ingredient of this paper is the study of a non-degenerate property of the Jacobian process of Xt.
Similar content being viewed by others
Data Availability
No datasets were generated or analysed during the current study.
References
Baudoin, F., Nualart, E., Ouyang, C., Tindel, S.: On probability laws of solutions to differential systems driven by a fractional Brownian motion. Ann. Probab. 44(4), 2554–2590 (2016). MR3531675
Baudoin, F, Hairer, M: A version of Hörmander’s theorem for the fractional Brownian motion. Probab. Theory Relat. Fields 139(3–4), 373–395 (2007). MR2322701
Cass, T, Friz, P: Densities for rough differential equations under Hörmander’s condition. Ann. Math. (2) 171(3), 2115–2141 (2010). MR2680405
Cass, T, Hairer, M, Litterer, C, Tindel, S: Smoothness of the density for solutions to Gaussian rough differential equations. Ann. Probab. 43 (1), 188–239 (2015). MR3298472
Cass, T, Litterer, C, Lyons, T: Integrability and tail estimates for Gaussian rough differential equations. Ann. Probab. 41(4), 3026–3050 (2013). MR3112937
Chevyrev, I, Ogrodnik, M: A support and density theorem for Markovian rough paths. Electron. J. Probab. 23, Paper No. 56, 16 (2018). MR3814250
Friz, P, Victoir, N: On uniformly subelliptic operators and stochastic area. Probab. Theory Relat. Fields 142(3–4), 475–523 (2008). MR2438699
Friz, P K, Victoir, N B: Multidimensional Stochastic Processes as Rough Paths: Theory and Applications, vol. 120. Cambridge University Press, Cambridge (2010)
Hairer, M., Pillai, N.S.: Ergodicity of hypoelliptic SDEs driven by fractional Brownian motion. Ann. Inst. Henri Poincaré Probab. Stat. 47(2), 601–628 (2011). MR2814425
Hairer, M.: On Malliavin’s proof of Hörmander’s theorem. Bull. Sci. Math. 135(6–7), 650–666 (2011). MR2838095
Hairer, M., Mattingly, J.C.: A theory of hypoellipticity and unique ergodicity for semilinear stochastic PDEs. Electron. J. Probab. 16, 658–738 (2011). MR2786645
Hairer, M., Pillai, N.S.: Regularity of laws and ergodicity of hypoelliptic SDEs driven by rough paths. Ann. Probab. 41(4), 2544–2598 (2013). MR3112925
Hörmander, L.: Hypoelliptic second order differential equations. Acta Math. 119, 147–171 (1967). MR222474
Inahama, Y.: Malliavin differentiability of solutions of rough differential equations. J. Funct. Anal. 267(5), 1566–1584 (2014). MR3229800
Lejay, A.: Stochastic differential equations driven by processes generated by divergence form operators. I. A Wong-Zakai theorem. ESAIM Probab. Stat. 10, 356–379 (2006). MR2247926
Malliavin, P.: Stochastic calculus of variation and hypoelliptic operators. In: Proceedings of the International Symposium on Stochastic Differential Equations (Research Institute Math. Sci., Kyoto University, Kyoto, 1976). MR536013, pp 195–263. Wiley, New York-Chichester-Brisbane (1978)
Norris, J.: Simplified Malliavin calculus. In: Séminaire de Probabilités, XX, 1984/85. MR942019, pp 101–130 (1986)
Nualart, D.: The Malliavin Calculus and Related Topics, 2nd edn. Probability and its Applications (New York). Springer, Berlin (2006). MR2200233
Revuz, D., Yor, M.: Continuous Martingales and Brownian Motion, vol. 293. Springer Science & Business Media (2013)
Acknowledgements
The author is grateful to Fabrice Baudoin for many insightful discussions.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Partial financial support was received from National Science Foundation grant DMS-1901315.
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Yang, G. A Version of Hörmander’s Theorem for Markovian Rough Paths. Potential Anal 60, 173–195 (2024). https://doi.org/10.1007/s11118-022-10046-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11118-022-10046-5