EN
For α ∈ (1,2) we consider the equation $∂_t u = Δ^{α/2}u + b·∇u$, where b is a time-independent, divergence-free singular vector field of the Morrey class $M₁^{1-α}$. We show that if the Morrey norm $||b||_{M₁^{1-α}}$ is sufficiently small, then the fundamental solution is globally in time comparable with the density of the isotropic stable process.