Constraints on Exotic Matter for An Emergent Universe
  We study a composition of normal and exotic matter which is required for a
flat Emergent Universe scenario permitted by the equation of state
(EOS)($p=A\rho-B\rho^{1/2}$) and predict the range of the permissible values
for the parameters $A$ and $B$ to explore a physically viable cosmological
model. The permitted values of the parameters are determined taking into
account the $H(z)-z$ data obtained from observations, a model independent BAO
peak parameter and CMB shift parameter (WMAP7 data). It is found that although
$A$ can be very close to zero, most of the observations favours a small and
negative $A$. As a consequence, the effective Equation of State parameter for
this class of Emergent Universe solutions remains negative always. We also
compared the magnitude ($\mu (z)$) vs. redshift($z$) curve obtained in the
model with that obtained from the union compilation data. According to our
analysis the class of Emergent Universe solutions considered here is not ruled
out by the observations.
