  A modified theory of gravity, avoiding singularities in the standard theory
of gravitation, has been developed by Hess & Greiner, known as the
pseudo-complex theory of gravitation. The pc-GR theory shows remarkable
observational differences with respect to standard GR. The intensity profiles
are significantly different between both theories, which is a rare phenomenon
in astrophysics. This will allow robust tests of both theories using Event
Horizon Telescope (EHT) observations of the Galactic Center. We also predict
the time evolution of orbiting matter. In this paper we summarize the
observational tests we have developed to date. The theory is described in the
second paper of this series (Hess et al. 2019, referred to as paper II
hereafter).
