A note on biharmonic submanifolds of product spaces

7 pages, à paraître dans Journal of GeometryInternational audienceWe investigate biharmonic submanifolds of the product of two space forms. We prove a necessary and suifficent condition for biharmonic submanifolds in these product spaces. Then, we obtain mean curvature estimates for proper-biharmonic submanifold of a product of two unit spheres. We also prove a non-existence result in the case of the product of a sphere and a hyperbolic space