New agegraphic dark energy as a rolling tachyon
  Combining the general relativity and the uncertainty relation in quantum
mechanics, the energy density of quantum fluctuations of space-time can be
viewed as dark energy. The so-called agegraphic dark energy model is just based
on this viewpoint, in which the age of the universe is introduced as the length
measure. Recently, the new agegraphic dark energy model was proposed, where the
dynamical dark energy is measured by the conformal age of the universe. On the
other hand, scalar-field dark energy models like tachyon are often regarded as
an effective description of some underlying theory of dark energy. In this
paper, we show that the new agegraphic dark energy can be described completely
by a tachyon scalar-field. We thus reconstruct the potential and the dynamics
of the tachyon scalar-field, according to the evolution of the new agegraphic
dark energy.
