Observational constraints on the unified dark matter and dark energy
  model based on the quark bag model
  In this work we investigate if a small fraction of quarks and gluons, which
escaped hadronization and survived as a uniformly spread perfect fluid, can
play the role of both dark matter and dark energy. This fluid, as developed in
\citep{Brilenkov}, is characterized by two main parameters: $\beta$, related to
the amount of quarks and gluons which act as dark matter; and $\gamma$, acting
as the cosmological constant. We explore the feasibility of this model at
cosmological scales using data from type Ia Supernovae (SNeIa), Long Gamma-Ray
Bursts (LGRB) and direct observational Hubble data. We find that: (i) in
general, $\beta$ cannot be constrained by SNeIa data nor by LGRB or H(z) data;
(ii) $\gamma$ can be constrained quite well by all three data sets,
contributing with $\approx78\%$ to the energy-matter content; (iii) when a
strong prior on (only) baryonic matter is assumed, the two parameters of the
model are constrained successfully.
