  We consider irreducible unitary representations $A_i$ of G=SO(n+1,1) with the
same infinitesimal character as the trivial representation and representations
$B_j$ of H=SO(n,1) with the same properties and discuss H-equivariant
homomorphisms Hom_H($A_i,B_j$). For tempered representations our results
confirm the predictions of conjectures by B. Gross and D. Prasad.
