  This research aims to introduce a new principle in the flat space-time
geometry through the elimination of the classical idea of rest and by including
a universal minimum limit of speed in the quantum world. This limit,
unattainable by the particles, represents a preferred inertial reference frame
associated with a universal background field that breaks Lorentz symmetry.
There emerges a new relativistic dynamics where a minimum speed forms an
inferior energy barrier. One of the interesting consequences of the existence
of such a minimum speed is that it prevents the absolute zero temperature for
an ultracold gas according to the third law of thermodynamics. So we will be
able to provide a fundamental dynamical explanation for the third law through a
connection between such a phenomenological law and the new relativistic
dynamics with a minimum speed.
