  The restoration of spontaneous symmetry breaking for a scalar field theory
for an accelerated observer is discussed by the one-loop effective potential
calculation and by considering the effective potential for composite operators.
Above a critical acceleration, corresponding to the critical restoration
temperature,T_c, for a Minkowski observer by Unruh relation, i.e. a_c/2\pi=T_c,
the symmetry is restored. This result confirms other recent calculations in
effective field theories that symmetry restoration can occur for an observer
with an acceleration larger than some critical value. From the physical point
of view, a constant acceleration is locally equivalent to a gravitational field
and the critical acceleration to restore the spontaneous symmetry breaking
corresponds to a huge gravitational effect which, therefore, prevents boson
condensation.
