The effect of different boost expressions, pertinent to the instant, front
and point forms of relativistic quantum mechanics, is considered for the
calculation of the ground-state form factor of a two-body system in simple
scalar models. Results with a Galilean boost as well as an explicitly covariant
calculation based on the Bethe-Salpeter approach are given for comparison. It
is found that the present so-called point-form calculations of form factors
strongly deviate from all the other ones. This suggests that the formalism
which underlies them requires further elaboration. A proposition in this sense
is made.Comment: Invited talk given at the 18th European Conference on Few-Body
Problems in Physics, Bled, Slovenia, 8-14 Sep 2002. Submitted to Few Body
Syst.Supp
