  We show that gravity together with curved spacetime can emerge, at the
microscopic scale, from a U(1) gauge field. The gauge boson that carries
gravity, of elementary particles, is proved to be a spin one massless and
electrically neutral vector particle dubbed the "gamma boson" referring to the
Dirac matrices, gamma_mu, which are promoted to be the quantum field for
gravity at the scale of elementary particles. Instead, the graviton appears
merely as a tensor bound state of two gamma bosons in the same spin eigenstate,
by referring to the relation g_mu nu = 1/2 (gamma_mu gamma_nu + gamma_nu
gamma_mu) and the metric ds^2 = g_mu nu dx^mu dx^nu = (gamma_alpha dx^alpha)^2.
Consequently, like the electroweak theory and quantum chromodynamics, gravity
may be formalized as a Yang-Mills theory. As a consequence, there is no need of
the Higgs field or any symmetry breaking mechanism to generate the mass of
fundamental particles. We show that one can get rid of the Yukawa couplings in
favor of the covariant derivative. Finally, a set of partial differential
equations that is equivalent to Einstein equations is established for the gamma
boson. Static spherical symmetric external solutions leading to the
Schwarzschild metric are found by solving the latter neglecting the mass
density of the gravitational field itself. Taking into account the latter
involves a departure from the Schwarzschild solution that may be tested by
laboratory experiments or astrophysical observations.
