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On Girsanov's transform for backward stochastic differential equations

11/2010;
Source: arXiv

ABSTRACT By using a simple observation that the density processes appearing in Ito's martingale representation theorem are invariant under the change of measures, we establish a non-linear version of the Cameron-Martin formula for solutions of a class of systems of quasi-linear parabolic equations with non-linear terms of quadratic growth. We also construct a local stochastic flow and establish a Bismut type formula for such system of quasi-linear PDEs. Gradient estimates are obtained in terms of the probability representation of the solution. Another interesting aspect indicated in the paper is the connection between the non-linear Cameron-Martin formula and a class of forward-backward stochastic differential equations(FBSDEs). Comment: 21 pages

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