On the Lagrange multiplier method to the Euler and Navier-Stokes equations on compact Riemannian manifolds
摘要
In this paper, we use the Lagrange multiplier method to derive the incompressible Euler and Navier-Stokes equations on a compact Riemannian manifold M, in which the pressure is given by a variant of the Lagrange multiplier for the incompressibility condition div u = 0. Moreover, we give a new derivation of the incompressible Navier-Stokes equations on a compact Riemannian manifold M via the Bellman dynamic programming principle on the infinite-dimensional group G = Diff(M) of diffeomorphisms. In particular, in the inviscid case, we give a new derivation of the incompressible Euler equation on a compact Riemannian manifold M. Our method provides an explicit construction of a solution to the incompressible Euler and Navier-Stokes equations via the value function and the Lagrange multiplier of a deterministic and stochastic optimal control problem on G = Diff(M).