Primordial power spectrum from a matter-Ekpyrotic bounce scenario in
  loop quantum cosmology
  A union of matter bounce and Ekpyrotic scenarios is often studied in an
attempt to combine the most promising features of these two models. Since
non-perturbative quantum geometric effects in loop quantum cosmology (LQC)
result in natural bouncing scenarios without any violation of energy conditions
or fine tuning, an investigation of matter-Ekpyrotic bounce scenario is
interesting to explore in this quantum gravitational setting. In this work, we
explore this unified phenomenological model for a spatially flat
Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe in LQC filled with dust
and a scalar field in an Ekpyrotic scenario like negative potential. Background
dynamics and the power spectrum of the comoving curvature perturbations are
numerically analyzed with various initial conditions and a suitable choice of
the initial states. By varying the initial conditions we consider different
cases of dust and Ekpyrotic field domination in the contracting phase. We use
the dressed metric approach to numerically compute the primordial power
spectrum of the comoving curvature perturbations which turns out to be almost
scale invariant for the modes which exit the horizon in the matter-dominated
phase. But, in contrast with a constant magnitude power spectrum obtained under
approximation of a constant Ekpyrotic equation of state using deformed algebra
approach in an earlier work, we find that the magnitude of power spectrum
changes during evolution. Our analysis shows that the bouncing regime only
leaves imprints on the modes outside the scale-invariant regime. However, an
analysis of the spectral index shows inconsistency with the observational data,
thus making further improvements in such a model necessary.
