Biharmonic maps between warped product manifolds

Biharmonic maps between warped products are studied. The main results are: (i) the condition for the biharmonicity of the inclusion of a Riemannian manifold N into the warped product M x (f2) N and of the projection pi : M x (f2) N -> M; (ii) the construction of two new classes of non-harmonic biharmonic maps using products of harmonic maps phi = 1(M) x psi : M x N -> M x N and warping the metric on their domain or codomain; (iii) the study of three classes of axially symmetric biharmonic maps, using the warped product setting. (c) 2006 Elsevier B.V. All rights reserved.