On the Heat Flow for Harmonic Maps with Potential

Let (M, g) and (N, h) be twoconnected Riemannian manifolds without boundary (M compact,N complete). Let G C (N): ifu: M N is a smooth map, we consider the functional E _G (u) = (1/2) _M |du|²– 2G(u)]dV _M and we study its associated heat equation. Inthe compact case, we recover a version of the Eells–Sampson theorem,while for noncompact target manifold N, we establishsuitable hypotheses and ensure global existence and convergence atinfinity. In the second part of the paper, we study phenomena of blowingup solutions.