• Media type: E-Article
  • Title: Densities for rough differential equations under Hörmander's condition
  • Contributor: Cass, Thomas; Friz, Peter
  • imprint: Dept. of Mathematics, Princeton University, 2010
  • Published in: Annals of Mathematics
  • Language: English
  • ISSN: 0003-486X
  • Origination:
  • Footnote:
  • Description: <p>We consider stochastic differential equations dY = V (Y) dX driven by a multidimensional Gaussian process X in the rough path sense [T. Lyons, Rev. Mat. Iberoamericana 14, (1998), 215—310]. Using Malliavin Calculus we show that Y t admits a density for t ∈ (0,T] provided (i) the vector fields V = (V₁,…,V d ) satisfy Hörmander's condition and (ii) the Gaussian driving signal X satisfies certain conditions. Examples of driving signals include fractional Brownian motion with Hurst parameter H &gt; 1/4, the Brownian bridge returning to zero after time T and the Ornstein-Uhlenbeck process.</p>
  • Access State: Open Access