This paper establishes the local-in-time existence and uniqueness of solutions to the viscous, non-resistive magnetohydrodynamics (MHD) equations in $\mathbb{ R}^d$, $d=2,3$, with initial data $B_0\in H^s(\mathbb{ R}^d)$ and $u_0\in H^{ s-1+\varepsilon}(\mathbb{ R}^d)$ for $s>d/2$ and any $0<\varepsilon<1$. The proof relies on maximal regularity estimates for the Stokes equation. The obstruction to taking $\varepsilon=0$ is explained by the failure of solutions of the heat equation with initial data $u_0\in H^{ s-1}$ to satisfy $u\in L^1(0,T;H^{ s+1})$; we provide an explicit example of this phenomenon.
Categories: math.AP