The Experts below are selected from a list of 24273 Experts worldwide ranked by ideXlab platform

Magdalena Kobylanski - One of the best experts on this subject based on the ideXlab platform.

Alexandre Popier - One of the best experts on this subject based on the ideXlab platform.

San J Martin - One of the best experts on this subject based on the ideXlab platform.

E Weinan - One of the best experts on this subject based on the ideXlab platform.

  • deep learning based numerical methods for high dimensional parabolic partial differential equations and backward stochastic differential equations
    Communications in Mathematics and Statistics, 2017
    Co-Authors: E Weinan, Jiequn Han, Arnulf Jentzen
    Abstract:

    We study a new algorithm for solving parabolic partial differential equations (PDEs) and backward stochastic differential equations (BSDEs) in high dimension, which is based on an analogy between the BSDE and reinforcement learning with the gradient of the solution playing the role of the policy function, and the loss function given by the error between the prescribed Terminal Condition and the solution of the BSDE. The policy function is then approximated by a neural network, as is done in deep reinforcement learning. Numerical results using TensorFlow illustrate the efficiency and accuracy of the studied algorithm for several 100-dimensional nonlinear PDEs from physics and finance such as the Allen–Cahn equation, the Hamilton–Jacobi–Bellman equation, and a nonlinear pricing model for financial derivatives.

Khaled Bahlali - One of the best experts on this subject based on the ideXlab platform.

  • quadratic bsde with mathbb l 2 Terminal data krylov s estimate ito krylov s formula and existence results
    Annals of Probability, 2017
    Co-Authors: Khaled Bahlali, M'hamed Eddahbi, Youssef Ouknine
    Abstract:

    We establish a Krylov-type estimate and an Ito–Krylov change of variable formula for the solutions of one-dimensional quadratic backward stochastic differential equations (QBSDEs) with a measurable generator and an arbitrary Terminal datum. This allows us to prove various existence and uniqueness results for some classes of QBSDEs with a square integrable Terminal Condition and sometimes a merely measurable generator. It turns out that neither the existence of exponential moments of the Terminal datum nor the continuity of the generator are necessary to the existence and/or uniqueness of solutions. We also establish a comparison theorem for solutions of a particular class of QBSDEs with measurable generator. As a byproduct, we obtain the existence of viscosity solutions for a particular class of quadratic partial differential equations (QPDEs) with a square integrable Terminal datum.

  • quadratic bsdes with l 2 Terminal data existence results krylov s estimate and ito krylov s formula
    arXiv: Probability, 2014
    Co-Authors: Khaled Bahlali, M'hamed Eddahbi, Youssef Ouknine
    Abstract:

    In a first step, we establish the existence (and sometimes the uniqueness) of solutions for a large class of quadratic backward stochastic differential equations (QBSDEs) with continuous generator and a merely square integrable Terminal Condition. Our approach is different from those existing in the literature. Although we are focused on QBSDEs, our existence result also covers the BSDEs with linear growth, keepingsquare integrable in both cases. As byproduct, the existence of viscosity solutions is established for a class of quadratic partial differential equations (QPDEs) with a square integrable Terminal datum. In a second step, we consider QBSDEs with measurable generator for which we establish a Krylov's type a priori estimate for the solutions. We then deduce an Ito-Krylov's change of variable formula. This allows us to establish various existence and uniqueness results for classes of QBSDEs with square integrable Terminal Condition and sometimes a merely measurable generator. Our results show, in particular, that neither the existence of expo- nential moments of the Terminal datum nor the continuity of the generator are necessary to the existence and/or uniqueness of solutions for quadratic BSDEs. Some comparison theorems are also established for solutions of a class of QBSDEs.

  • Multidimensional BSDEs with super-linear growth coefficient: Application to degenerate systems of semilinear PDEs
    Comptes Rendus Mathematique, 2010
    Co-Authors: Khaled Bahlali, El Hassan Essaky, M. Hassani
    Abstract:

    Abstract We establish the existence and uniqueness as well as the stability of p-integrable solutions to multidimensional backward stochastic differential equations (BSDEs) with super-linear growth coefficient and a p-integrable Terminal Condition ( p > 1 ) . The generator could neither be locally monotone in the variable y nor locally Lipschitz in the variable z. As application, we establish the existence and uniqueness of weak (Sobolev) solutions to the associated systems of semilinear parabolic PDEs. The uniform ellipticity of the diffusion matrix is not required. Our result covers, for instance, certain systems of PDEs with logarithmic nonlinearities which arise in physics.