%0 Journal Article %T Hybrid bounds for automorphic forms on ellipsoids over number fields %A Valentin Blomer %A Philippe Michel %J Mathematics %D 2011 %I arXiv %R 10.1017/S1474748012000874 %X We prove upper bounds for Hecke-Laplace eigenfunctions on certain Riemannian manifolds of arithmetic type. The manifolds under consideration are d-fold products of 2-spheres or 3-spheres, realized as adelic quotients of quaternion algebras over totally real number fields. %U http://arxiv.org/abs/1110.4526v2