Chaplygin gas and the cosmological evolution of alpha
  The class of Chaplygin gas models regarded as a candidate of dark energy can
be realized by a scalar field, which could drive the variation of the fine
structure constant $\alpha$ during the cosmic time. This phenomenon has been
observed for almost ten years ago from the quasar absorption spectra and
attracted many attentions. In this paper, we reconstruct the class of Chaplygin
gas models to a kind of scalar fields and confront the resulting
$\Delta\alpha/\alpha$ with the observational constraints. We found that if the
present observational value of the equation of state of the dark energy was not
exactly equal to -1, various parameters of the class of Chaplygin gas models
are allowed to satisfy the observational constraints, as well as the
equivalence principle is also respected.
