Long‐Time Solvability and Asymptotics for the 3D Rotating MHD Equations

We consider the initial value problem for the 3D incompressible rotating MHD equations around a constant magnetic field. We prove the long‐time existence and uniqueness of solutions for small viscosity coefficient and high rotating speed. Moreover, we investigate the asymptotic behavior of solutions in the limit of vanishing viscosity and fast rotation, and show that the velocity and magnetic field converge to the zero vector and the solution to the linear heat equation, respectively. We also derive the rates of these convergences in some space‐time norm.